Conference 7.286::home_work

    	I have a 2 1/2 story Victorian that I just had completely 
        insulated. The blown in portion was done from the outside. The 
        contractor removed two rows of clap board, one on the top and 
        one on the bottom, from each floor. Then he drilled holes 
        between EVERY stud to blow in the insulation. If you insulate 
        from the inside you will have to repair all these holes in the 
        living area. Don't forget bay windows. To completely insulate 
        them from the inside you may have to drill through floors or 
        ceilings.
    
    	Your best bet is doing it from the outside. Go to your local 
        paint store and have them mix an exact match for your house 
        from a paint chart. One gallon was more than enough for my 
        house.
    
    	               Fred
    

One of the reasons that I'm such a fan of The Old-House Journal (see separate
note) is that one of the first issues we received carried very strong warnings
about insulating the walls of an old house:

    DO NOT insulate any wall without installing a vapor barrier covering
    100% of the inside walls.  Without this vapor barrier, the insulation
    (which is usually blown-in cellulose) becomes a sponge, trapping
    water vapor within the walls.  The typical result within a few years
    is peeling exterior paint and slowly rotting walls.

The best interior vapor barrier is the plastic sheeting used in new
construction.  Other alternatives include vinyl wallpaper or special vapor
barrier paint.

I understand that most insulating contractors do not deal with this vapor
barrier issue.  I suspect that if they did, it would cut out a significant
portion of their customer base.

-- Ward

Another consideration in insulating the walls of an old house is the
effectiveness of such insulation.

In a typical uninsulted old house, the major heat losses are through the roof
and around or through windows and doors.  Correcting these heat loss areas will
usually make a much bigger difference in heating cost than insulating walls. 

-- Ward

          After reading the responses  i am now confused 
about this issue! I believe that without the vapor barrier moisture
will ruin the insulation, but why have so many people done this? 
 Is there another type of isulation to use for this purpose?

   and how much heat is actually lost through uninsulated walls?

the house i'm talking about is 80+ years old, if i seal the cracks and such,
and insulate the attic will this be enough?



paul

I don't exactly remember the number but 85% heat loss through roof and windows,
doors, etc comes to mind.  That is to say that you lose 15% heat through
non-insulated walls and 85% though the roof/windows,doors

RE .2

The Old House Journal is absolutely right.  Our next door neighbor had
insulation blown into the walls of his victorian house, and then had it
painted.  The paint job lasted one year.  After only two years the peeling
paint is in much worse condition than before he did the insulation.

-Mary

re: .0  also .4(?), & .6?

From my brief reading of the OLD House Compendium, I believe I recall two
aspects of the "vapor barrier", and also of peeling paint.

No. 1 - Vapor barrier - If a vapor barrier is used at all, it should be in-
stalled on the inside wall. The OHC does recommend both cellulose, provided
it has been treated with baking soda for vapor drying and prevents the paper
(cellulose) from getting soggy. ( My offic neighbor claims the cellulose
loses effectivity in 3+ years, but is easier to blow than fibre_glass).

No. 2 - Paint peeling is generally caused by excess moisture, and not enough
"breathability". There is small disc_like device which shoiuld be installed
wherevver necessary to allow "breathing", which will alleviate the mosture
problem. I get the impression it might be becessary (on a large house) to
install a lot of these little "louvers" (lots = 100 + ??).

( SOme paint peeling is also caused by othe factors, such as lack of proper
surface preparation, mildew, Oil Paint over Water base paint (or vice versa)).

Again, I need to point out the excellent advice on the OHC.( I am painting
my house in stages, will probably take 5 years, but I am bound and determined
to scrape, prime, then paint with OIL base (personal preference).

BTW. All the leading paint manufacturer which "guarantee" their paint, only
offer to replace the PAINT itself (no labor charges), and that guarantee
is stated that proper surface preparation must be done. ( To me, it sort
of reads like the older auto warranties ... if in the opinion of the dealer
or manufacturers representative ... ).

After spending $25+ per gallon, and several weeks of painting, I don't want
to go back to the store only to hear ( ... well, sir, it states right here
..).

						Bob

We purchased a house that is about 35 years old. After finding out from the
previous owners how much it cost to heat (oil fired FHA) I made a list of
what would improve the energy situation. The burner was running at about
70% efficiency, the windows were double hung single glazed (maybe R .5-1)
and I'm sure the insulation in the walls was minimal. There was blown in
cellulose in the attic. What I did was to first replace the oil burner with
a new Beckett then I replaced all the windows with Pella double hung double
glazed. (R 2.5 est.) I had asked the home inspector about having blown
in insulation for the walls and his reply was that he felt that plaster and
rock lath walls would provide a reasonable amount of insultaion and I should
consider this task as a last resort. Also I added a Honeywell T8200 programm-
able thermostat for the set back benefits. Well, to make a long story short
I'm glad we didn't have insulation put into the walls. The house is quite
toasty with the new windows mainly and the more efficient burner.

Pat
(the windows were a fun  DIY challenge)

re: .-1

	Where did you buy the thermostat?  Anything particularly good about
the Honeywll?

__Rich

Paul
	I blew in cellulose last fall in a 120 year old house.  The horsehair
plaster walls were in bad shape.
	I made 2 1/2 inch holes through the lath with the ol' drill and
hole saw combo.  (make enough.  The contracter I got an estimate from
said they would do 2 holes in 8 feet... better 3: the stuff won't settle.
also use enough.  I ended up using 50-75% more than the minimum coverage
on the bag.  It's cheap and if you do it yourself, labor is free, so
be generous.)
	Anyway, patching consisted of using said hole saw to cut 2 1/2
inch circles from sheet rock, and filling the holes with these. 
And the rest, you guessed it, is tape and joint compound.  Use a wide
knive and feather out a long way.
	The other alternative is to drop a mesh in the hole and use
patching plaster.   Either way.
	It does take some work, but believe me, IT'S WORTH IT.
Also, do it yourself.  I got an estimate for $1500 and did it for $250.00
myself, which of course paid itself off real quickly.
		Charlie Crabb
		hlo2-2/G13
		225-5739

ps:
	In regards to the previous replies: Beware of mythology.
	1)  Use vapor barrier paint inside.
	2)  A house 80 years old has 1x...sheathing boards, not
	    plywood or particle board as in modern homes.  The
	    joints between the boards will breath.
	3)  Don't put anything on the outside to hinder this
	    process (aluminum siding, homosote...)
	4)  "Losing effectiveness" mythology.  If you drill enough
	    holes, cellulose won't settle.  As I said, use enough.
	    I did an experiment.  I was able to get at the wall from
	    the top plate and stuff the cellulose in by hand or blow it
	    in and check the density.  As I said, use 50-75% more that
	    the recommended density on the bag.
	5)  You CAN get blowable fiberglass, but it is not as effective:
	    It doesn't pack as well.
	6)  Some of the holes I made were not plugged for a year.
	    (Well I work here too.)  so I was able to "look in "
	    at the celullose and watch for settling.  None.
	7)  Finally, you might consider another interesting phenomenon
	    in old houses.  Because there are joints in the sheathing,
	    there are drafts in uninsulated walls.  So not only are you
	    losing heat through convection and conduction through an
	    R 2-4 airspace in the walls, but there is forced convection
	    from the cracks.  You're losing more than you think, so
	    insulating is a good idea.

Packing in extra insulation may guarantee that it won't settle, but you'll
also lose a lot of the R-value of the insulation.  Cellulose (or fiberglass,
or anything else) has an optimum density to achieve maximum insulating
value.  

I believe the original note said that you're planning to redo the interior
walls sometime anyway.  If you are, then there's no point in blowing in
insulation; it will all fall out when you tear down the interior wall.
I think I'd forego the insulation for now and do each room when I redid
the walls in that room.  I'd use fiberglass batts, with a polyethylene
vapor barrier.
If by "redo the walls" you don't mean "tear down and replace", of course
that doesn't apply.  However, that option might be worth considering.
I cannot get very excited about blown-in insulation, no matter how good
it's supposed to be.  

Steve

The whole argument about packing insulation went on recently in the letters
section of Fine Homebuilding.  Basically what it comes down to is: any
insulation batt will insulate better the less it is packed in.  For example,
a 6" batt is rated at r19.  Packed into 3.5 inches instead of 6, it is rated
at about 14.  Past its rated thickness it also decreases, so if you stretched
a 6" batt out to 8", it would have less than r19.

But, given a certain depth of wall space, you can get better insulating value
by packing in more than the rated amount of insulation.  In the example above,
a 6" batt in a 3.5 inch space is about R14.  A 3.5 inch batt in the same space
rates only about R11.  Similarly, an 9" batt stuffed into a 6" space will give
an R value of about 22.5, whereas the normal 6" batt will give only R19.

So if you are insulating an attic, where you do not have a confined space to 
worry about, you should keep the insulation as well fluffed as possible.  BUt
if you are insulating a wall, with a pre-defined space to fill, you will get the
best insulation value by overpacking slightly.  Further packing does not bring
significant gain, for example a 9" batt in 3.5 inches is between R14 and 14.5,
so you've bought 3" of extra insulation (over the 6" batt), but gained less
than a half of an R.

For most people the extra cost of the extra insulation is only marginally worth
it, but it does yield the highest R value for the given wall space.

Paul

    Judging from the dates on the responses to this note, this comment
    may be too late.  I had an energy audit done on my 100 year old
    house and one of the questions asked was whether or not my house
    was backplastered.  Not knowing what backplastering was, I asked
    the auditor.  He explained that at one time builders would erect
    the stud wall, sheath the exterior and then plaster the inside
    of the exterior sheathing.  This, along with the interior plaster
    wall effectively sealed the wall cavity and worked well enough that
    the payback for blowing in insulation would be very long.  I checked
    my house and it was backplastered; you may also want to check yours.  

    This may be another late reply but... I have a 150+ year old house
    which I have had insulation blown into, yes it was celuose in 
    the walls. I had it done about 14 years ago. I have never regretted
    doing it, however if you plan to dedo the inside, in the near future
    don't blow any insualtion into the walls.. 1) you will have waisted
    money and 2) that stuff will make an unbelieveable mess if you cut
    into a wall that its in. The stuff is usually packed in there so
    tight that it explodes into fine dust when it is exposed.
    
    dave

I'm adding two bedrooms to my upstairs, (it's a Cape).  My
question is, what is the best way to insulate this area...
I'm also going to use behind the walls as a storage area..
I don't want to much insulation, but want enough for it to
stay comfortable through winter....  We'll be heating with
coal..  I've heard alot of different views on to how to go
about this.  Some people say, 'just insulate the roof' and
some people say, 'just insulate the walls'.....  I've also
heard to insulate them both..  The floor already has blown
in insulation (I've been told to get rid of that) and I've
been told to leave it.  I'm so confused..  I want to do it
right.  Any idea's?????





						Thanks / Dan

    
    I'm working on finishing the upstairs of a gambrel (master bedroom
    done, everything else insulated, framed, and rocked.  If you're in New
    England, insulate the walls AND ceiling, and don't bother removing the
    stuff in the floor...it's good for sound deadening and it doesn't hurt
    to have it there for thermal reasons, like when you come home on a hot
    summer day, you'll find at least your first floor nice and cool.  Also,
    it's good to have if you want to heat your first floor in the winter
    without heating your bedrooms too much.  Besides that, it's a lot of
    work to remove, too.  I think the recommended amount of insulation is
    6" in the walls (if your studs are 2x6's) and 12" in the attic
    (fiberglas in both).  Also, you want to make sure there is air space
    between your insulation and roof sheathing so that air can flow between
    your soffit vents and gable or ridge vents. They make foam vent chutes
    for this purpose. 

    Hope this helps!
    
    						- Rich

    Amen to .1
    
    The stuff in the floor won't hurt, and can help.
    
    6" in the wall is becoming very popular, but don't try to stuff
    6" of insulation into a 4" wall (standard 2x4 construction) - you're
    just wasting money.
    
    Insulate the living space. In a cape, this usually means following
    the vertical wall, the roof joists in the sloped area, and the ceiling
    rafters. If you're using the space behind the vertical walls for
    storage, follow the roof joists from floor to ceiling. The standard
    thicknesses are 4" in walls (6" if space allows), 6" in roof joists
    and 12" above horizontal ceilings
    
                   ^                                ^
                  / \                              / \
                 /   \                            /   \
                /     \                          /     \
               /xxxxxxx\                        /xxxxxxx\
              /x/-----\x\                      /x/-----\x\
             /x/       \x\                    /x/       \x\
            /x/         \x\                  /x/         \x\
           / x|         |x \                /x|           |x\
          /  x|         |x  \              /x |           | x\
         /   x|         |x   \            /x  |           |  x\
        /    x|         |x    \          /x   |           |   x\

             (no storage)                       (storage)

    If you follow the roof line exclusively, you'll be heating a lot
    of space that you don't use.

    Why were you told to get rid of the insulation in the ceiling? Did
    it contain a hazardous material to your health? If not leave it!
    When I tore out the walls and ceiling's of my house, the first room
    I redid I put 6" in the ceiling as I did with the walls(with proper
    dead space).The other rooms I did not do this and wish I had. That
    room is the most comfortable and warm room in the house! Roof
    insulation is absolutely a must if you want to keep your heat bill
    down or rely on coal or wood heat.
    
    						Good Luck
    
    						   Rick
    

    I'd like to open a disscussion on this one time popular insulation
    material.  I myself have very little knowledge on urea formaldehyde,
    except that real-estate agents curse the day that legislation was
    passed on the stuff.
    
    The argument I here is that it really isn't bad for you as long
    as it is within "acceptable levels".  Even if that is the case,
    the unfortunate homeowners who have this insulation cannot escape 
    having the price of their house devalued accordingly.
    
    I'd like to know if anyone has this insulation (or has had it),
    and what they have experienced in the way of side-effects if any.
    Also, any suggestions or comments to a perspective buyer of a
    house endowed with UF.  I mean, if it really is bad what can one
    look foward to in de-formaldehyding a house.  Maybe we are just
    the victims of over-legislation by our government and UF really
    is an exellent insulation material???  Comments and/or horror
    stories welcome here...
    
    Thanks,   Rik Deere

    I know of one person who had their house insulated with 
    urea formaldahyde during the late 70's.  They moved from a
    populated area to an old farmhouse in the hills of central 
    Mass.  Since they had some children and limited budgets, they
    chose UF for its price and promises of lowering fuel bills that
    were skyrocketing through their roof.  
    This person and her husband were in good health, she was a nurse
    and he was a teacher.  They and their children were healthy until
    they moved into the house.  Since then they have been plagued with
    rashes, dermatitis, congestion, coughes, and possible asthma......
    They curse the day that they had it installed......

    My last house had UF.  So I've been through the hassles of both
    buying and selling a house with UF.  When I bought the house, the
    previous owner paid for the UF testing ($275).  Once the house passed
    the test, the bank wanted me to write a letter to them for their
    files.  The letter was just an acknowledgement on my part, that
    I knew the house had UF, and I wouldn't hold the bank responsible
    for any thing that resulted because of the UF.  (In other words
    - the bank just wanted to protect itself).  
    
    I didn't have any problems selling the house with UF.  But it was
    in the "starter house" price bracket, and that's a big market these
    days.  Lots of people are looking for houses they can afford!  The
    buyer's bank required the same type of letter, but didn't insist
    on a new UF test.  (I lucked out - I had offered to pay for the
    new test!)  
    
    As for UF itself.  I did a lot of research before I bought the house.
    The problems with UF are only if it was installed wrong.  If it
    is installed correctly, it's one of the best insulating materials.
    If it is installed wrong, it can produce a gas which is harmful.
    The legislation came after too many companies were installing it
    wrong.  I also found out, that if the UF isn't producing a gas now,
    (ie, passes the UF test without any trace of gas), then it will
    never produce a gas.  So since my house passed the test, I felt
    good trusting that the UF had been installed correctly and I wouldn't
    have a problem in the future.
    
    - Molly -

    some related info..
    
    	Apparently, what is meant by "incorrect installation" is that,
    because the stuff is injected in wall spaces, sometimes the nozzle
    would clog without the operator noticing.  When this happened, the
    foam may not expand and cure properly.
    
    

    As I understand it, the chemicals were mixed in the nozzle of the
    machine, or something similar, and if things wern't set up just
    right the proportions of the chemicals would be off or the mixture
    wouldn't be thorough enough, which would result in an incomplete
    chemical reaction and leftover stuff that would release noxious
    fumes into the house.  However, as pointed out, IF the job was
    done properly, no problem.  Unfortunately, given that a lot of
    allgeged contractors can't even install fiberglass installation
    properly, quite a few UF jobs came out bad....
    
    I've heard of shrinkage problems with UF too, independent of the
    quality of the installation job.  Nothing dangerous about it, of
    course, but it drops the efficiency of the insulation way down.
    
    Steve
    

    re:.2
    
    If that's the way banks are handling houses with UF I guess that
    one could assume that the only houses that are passing these tests
    are the ones that are selling.  Any others that are or were of the
    noxious fume variety, either are not selling or have had the UF
    removed by now.  It could very well be that, in general, if one
    were looking to buy a house with UF that it is probably just fine
    to live in it and not experience the kinds of problems noted in
    .1.  
    
    Rik

    I'm allergic to a wide range of things, from cats (mind you, I live
    with two anyway) & dogs to dust and pollen.  My allergist advised
    me to avoid UF like the plague.  It's just not worth getting involved
    with.
    
    	- Barry

    This is a very sore subject for me.  I belong to the Human ecology
    action league (HEAL) due to this stuff.  I could list some tales
    that would make your hair stand up.  Some from personal experence.
    
    Talk about toxic time bombs.  I have also sent the same samples
    to two different labatories and have one negative and one come out
    with a large parts per million count than is healthy.
    
    Best bet be informed.  Check out everything that is composed of
    chemical compounds.  Use them corectly to get the maximun off gassing
    before you seal it up in you living space.
    
    peace & good health

    The same chemicals are used in plywood and panelling. Once again,
    if the manufacturer is not careful with the mix, formeldahyde vapors
    escape. I read of one woman living in a mobile home who had symptoms
    of formeldahyde exposure. She didn't have urea-formeldahyde insulation
    but they found very high levels of the gas in her home being released
    from the panelling on the walls. Some manufacturers print a warning
    statement on the back side of the panels, presumably to escape
    liability. This stuff is like asbestos, it's everywhere.

    We have been living in a house that has UFFI for over three years,
    with no problems (that can be related to the UFFI). When we bought
    it the previous owners had an inspection done, and no traces of
    gas could be found. The previous owners had it installed because
    she was afraid of fires and felt UFFI was a better risk. He was
    a doctor, and told us he watched what they did carefully. The building
    inspector we hired could not tell there was UFFI in the house -
    and he said he almost always could detect at least a trace near
    the outlets.
    
    We have found that if you know contractors who installed it you
    *might* be able to have them take it out at their cost. To find
    out more call the State (I have the number at home if anyone is
    interested). There are some problems - most UFFI installers have
    since gone out of business, and you would have to pay to have new
    installation put in.
    

    There is a group of people interested in this, and they can be reached
    at:
    
    	UFFI Homeowners association
    	PO Box 918
    	West acton, Ma. 01720
    

    I have a house that was built a year ago and the contractor never
    put in a vapor barrier!  There is 6 inches of blown in insulation
    with ridge venting the length of the house. The house is a garrison
    with sprayed ceiling. The rice crispy type. I want to add more
    insulation. It would be hard to paint the ceilings with vapor barrier
    paint because of the texture. The question is would the added
    insulation retain moisture or would the venting take care of it?

    I seem to remember a recent article that questioned the value of a
    vapor barrier in actually keeping insulation dry. As I recall, it
    said that studies have shown little difference in the moisture content
    of insulation with or without vapor barriers installed. The key
    to keeping the insulation dry was in proper venting, and the advantage
    of any 'vapor' barrier was to stop air filtration and resultant
    heat loss. Anybody out there see the article and remember where
    it was published?
    
    The above notwithstanding, I doubt you would run into any moisture
    trapping problems using unfaced batts, or any other type of insulation
    without a vapor barrier, above the existing insulation. Just make
    sure you don't plug any existing venting paths.

    

When I was building an addition I wasn't sure of the best way to insulate it
so I called Owens Corning and asked to speak to someone in customer service.
They in turn transfered me to one of their engineers and we had a fine chat.

I would recommend the same thing and get the answer direct from the horse's
mouth.  Naturally they would be biased around their own products, but it sounds
like you're not asking a vendor specific question.

-mark

    RE: .1 You hit the nail on the head!
    
    Ventilation is the answer? As long as there is good ventilation
    there should be no moisture problems.
    
    Look at the number of older homes that have since had insulation
    added without vabor barriers.
    
    -Mike-
    

    I'm in the process of building my house and I had asked my insulating
    contractor the same question of why he wasn't putting in a vapor
    barrier on the ceiling. Basically what he said was that when it
    is installed on the ceiling, tests have shown that it causes more
    problems then it's worth (mildew in moist areas like the
    bathroom/kitchen, etc). He too, informed me that as long as the
    venting is good I will never have a problem.
    

    I'm glad you mentioned the moisture in the bathroom because I was
    going to paint the ceiling with a vapor barrier paint. It sounds
    like I could have been causing a problem by doing it. These comments
    are what I needed.
                                                                   thanks,
                                                                   Ed  
     

    Discussions on vapor barriers are similar to religion -- they arouse
    passions. I am a vapor barrier believer, but I will try not to get
    on my soapbox!
                  
    RE: .0        
                 
    You can safely add the insulation as long as you have adequate
    ventilation.  One easy way of determining whether your ventilation
    is adequate is to put a piece of plastic on top of the insulation
    in the attic over the bathroom area. Take a long shower with the
    windows closed. After an hour or so, remove the plastic. The top
    of the insulation will probably be damp. That dampness should evaporate
    within a hour if you have adequate ventilation!
                          
    RE .1
                                                 
    I think the article missed the point. A vapor barrier is not primarily
    intended to keep the insulation dry, it is intended to keep the
    moisture in the house. If the house has adequate ventilation then there
    could not be any difference in the moisture of the insulation -- but
    the inside of the house is warmer and more moist and therefore more
    comfortable. 
                                                                          
    RE .4                                                                 
                          
    A vapor barrier serves a number of purposes, and has a multitude of
    benefits. (I will keep off the soapbox by not listing all the
    wonderful things my vapor barrier does for me!) 
                 
    It does have one major "cost" and that is that the homeowner has to
    control the moisture level in the bathroom and possible the kitchen.
    This can easily be accomplished by having a kitchen/bathroom fan which
    is vented to the outside, with an automatic louver which closes
    whenever the fan is not in operation. If one uses the fan during 
    showers (or in the kitchen when cooking) it will eliminate all mildew,
    excess moisture, etc problems. 
                     
    The insulation contractor who built our house made us sign
    an agreement which holds him harmless if we have any problems caused
    by excessive moisture. In two winters of living in the house, we
    have had no problems -- and have a much more comfortable house because
    of the vapor barrier.                   
                                            
    RE .5                                   
                                            
1. I can not say for certain, but I do not believe that the "vapor barrier"
    paints actually act as a serious vapor barrier. Maybe someone else
    in this conference has read to the contrary, but I have read that
    such paint is a rip-off.                
                                            
2.  If the paint actually did work: Do you have a dry house in the
    winter? Do you have forced hot air heat?  Do you have a bathroom
    fan?  If your answers are yes, I would use the paint. You can control
    any excess moisture with the fan, while making the house more
    comfortable without having to run a humidifier!  Oops I'm back on
    my vapor barrier soapbox -- sorry!.
                             
The bottom line is -- add your insulation and ventilate, ventilate,
ventilate!                             
                             

    Thanks, since there is no vapor barrier in my ceiling and there
    is already 6 inches of blown in insulation adding a vapor barrier
    is out of the question. Do you remember where you read that article
    on vapor barrier paints? I feel I have plenty of ventilation with
    a ridge venting system that covers the length of the house along
    with full soffit venting as well. I'm waiting for MASS SAVE to audit
    my house so I can get an idea as to add 3.5 inches more or go with
    6 inches of unfaced fiber glass roles. Everyone says they give a
    computer print out of the pay back to see if it's beneficial.
                                                                   
                                                              Ed

One of the things the Owans Corning guy told me that scared to to death was
simply this.  There is no such thing as a perfect vapor barrier due to things
like nail holes, etc.  However, the most important thing is that the porocity 
of the vapor barrier be lower than the porosity of the outside wall.  In other
words, any moisture passing through the vapor barrier needs to be able to get
outside.  In the case if ceiling, this is accomplished by venting.

However, in the case of wall, how does the moisture get out?  In the old days
this was never a problem because the wall were made of boards and had so many
air spaces that there was no problem in moisture escaping.  Today, there's a
different problem.  Whether plywood or particle boards the glue they're made
with is so waterproof, that moisture from within the wall gets trapped!  This
moisture can then build up and rot out the walls.

Obviously this isn't happening a lot, but with people trying to make their 
houses air tight, it can be a problem to be dealt with.

-mark

    
    	Hmmmm, last time I was in a manufacturing plant I read those
    big blue drums that they use for "foam_in_place" packing.  Don't
    remember the exact formulae, but I got the idea that its essentially
    the same stuff.
    
    	Reg
    

    
    
    Has anyone seen any insulation sales lately? Doesn't insulation
    usually go on sale this time of year?
    
    Also, I'll be buying some Prop-a-vent air channels for a cathedral
    ceiling but they're priced from $.79 to $1.30 for a 4 foot section.
    Has anyone seen good prices for those or are you aware of alternatives?
    
    Thanks....Rob
    
    
    

    Try Spags.  They have 7W bulbs too!

    Try Maki Lumber in Lunenberg.   I got my prop-a-vents there for
    about $1.30 for a 4-foot section.   However, the sections are for
    24-inch on-center joists.  You can split them, so each 4-foot section
    actually is 8 feet long.   Maki's price on regular insulation was
    less than the sale prices I found elsewhere, but I was buying for
    4 houses (4 of us were finishing our upstairs at the same time)
    so they did give me a small price break, and they delivered free,
    but it was almost $2000 of insulation...

    This won't help if you need with-vapor-barrier-type insulation, but my
    recent looking indicated 1) sale prices are tightly clustered around
    $0.25/sq ft for R-19 unfaced fiberglass (so it didn't seem to much
    matter where you bought, as long as it was on sale) and 2) cellulose
    insulation is far cheaper - $0.16/sq ft on sale at Wickes thru tomorrow
    (Sept. 27). Cellulose insulation is ground up, flame-retardant-treated
    newspaper, and must either be blown in or otherwise considerably fluffed
    up (i.e., not as convenient as fiberglass rolls.)
    
    Chuck

    Can anyone tell me how to calculate the payback on adding insulation
    in the attic. I have 6" of blown in insulation and would like to
    add 3" or 6" more, but where is my break even point? Can anyone
    shed some light?                                    
                                                                   Ed

    Hunt up a copy of the book "From the Walls In" by Charlie Wing.
    He goes into more detail about calculating payback that you'll
    probably ever want to know.  The book also has a heck of a lot
    of good information about remodeling, insulating, rebuilding, etc.
    
    Steve

    THE AMOUNT OF INSULATION THAT YOU WANT TO ADD DEPENDS ON YOUR HEAT
    SOURCE (WOOD, OIL, ELECTRIC) AND WHAT INSULATION IS IN THE WALLS,
    FLOORS ETC. FOR OIL, GAS, OR WOOD IT IS COST EFFECTIVE TO USE 12"
    OR R-38. FOR ELECTRIC HEAT (IF YOU ARE UNFORTUNATE!) R-57 OR 18" 
    OF FIBERGLASS IS REASONABLE. 
    
    ALSO THE AMOUNT OF INSULATION SHOULD BE BALANCED, R-60 IN THE CEILING
    DOESN'T DO MUCH GOOD IF THE WALLS AREN'T INSULATED. ALSO, HOW DRAFTY
    IS THE HOUSE? WHEN WAS THE LAST TIME THE FURNACE (BOILER?) SERVICED?
    GETTING THE FURNACE CLEANED, AND CAULKING AND WEATHERSTRIPPING
    EXTENSIVELY ARE THE MOST COST EFFECTIVE 1ST STEPS. I CAN THINK OF
    A NUMBER OF MORE SPECIFIC THINGS TO ASK, RATHER THAN RAMBLE ON HERE,
    GIVE ME A CALL.
    
    RICHARD CHASE
    ANT:: CHASE	 296-5862  617-869-6878
    

    I've recently seen a new insulation product in the stores.  It's
    basically foam-in-a-can.
    
    What is this stuff?  Has any consumer type agency checked into the
    safety of this stuff?
    
    What is the R-value per inch on this stuff?  Has anyone put it into
    their homes?  If so, any comments?
    
    I would hate to put the foam into my house and then find out 5 years
    later that it's another UFFI (Urea Formaldehyde Foam Insulation)
    in hiding.
    
    -al

It's not new, and it's great stuff.  There has been no safety issue regarding 
it at all as far as I know.  I think that it's R-value is about R5/inch.  Its 
one drawback is that it is quite expensive.  But for sealing cracks that are 
too big for caulk and too small for other insulation, you can't beat it.

It's especially good for sealing around windows between the window frame and 
the wall framing.

Paul

    It's a polyurethane foam that expands very nicely to fill irregular
    cracks or openings in hard to reach areas. The brand name I've seen
    most is Great Stuff, but there are others - should be available
    at most hardware stores for about $5 a can. That sounds expensive
    compared to a $1.50 tube of caulk, but I 'stuffed' my entire sill
    area (about 150 linear feet) with less than two cans. Its very sticky,
    so wear the gloves that come in the box, and old clothes!
    

      This 'great stuff ' is on sale at plywood ranch this week for
    99 cents a can! Regular 4.99... 3.00 off.... and 1.00 mail-in
    rebate. Not too shabby huh? Plywood Ranch is on Park Ave. near
    webster Sq. in Worcester.

    1)	If you can wait a little while for a sale or a promotion, do.  
    I've never seen a product that offered rebates as often as this. 
    
    2)	Don't buy a whole mess of cans and store them for years.  At
    least in my experience, even unstarted cans don't last more than
    12 months.  Once you use even a little out of one, it becomes unusable
    in weeks.
    
    -joet

    .3 snuck in on me while I was typing .4
    
    -joet

1) Spags has it cheap under misc. brand names

2) Pay attention to the applicator tube that comes with it -
unless you clear the tube (if you can) right after use, the tube 
becomes useless.  in some cases, this makes the can useless.

I spray it around all 'necessary' holes outside my house (a/c 
connections, gasmeter, hose pipe, etc)

    I saw it at Spags for $3.99/can, near the tulip bulbs.
    
    -al

    
    I'm currently in the process of building a new house and was wondering
    if it is economically feasible to do all around my windows with
    this stuff. I understand that "stuffing" fiberglass around the smaller
    spaces will stop infiltration, but "foam_in_a_can" seems like it
    might not only stop infiltration but also do a better job at
    conductive losses, yes?
    
    Also, what should I use in the rather large area at the bottom of
    the window underneath the sill?
    
    Charlie

Definitely use the foam.  It stops the infiltration far better than fiberglass 
ever could - I'm sure it will pay for itself because of the lower heat loss, 
plus it will be more comfortable near the windows.  If I could only use the 
foam for one thing, I'd use it for around windows.  And go ahead and use it 
under the sill too.  If you want to save some, stuff the back of that crack 
with fiberglass and then just foam the front, but make sure that the foam seals 
at both edges.

Also, for that amount of foam, you can get a contractor's size container.  They 
are about a gallon or two, and they have a flexible hose with a nozzle on the 
end.  It would be easier to use, too, since with the cans you always have to 
keep the nozzle pointed down.  With the hose you can keep the main drum upside 
down but put the nozzle any way you want.  Ask at your lumberyard for them.
We wound up using cans because they had them for sale for $2 apiece at 
Grossmans, and we bought about 30 cans.

Paul

    Thanks, Paul.
    
    I'll definitely go with the foam and that's an excellent suggestion
    about the sill area.
    
    Charlie

    foam in a can?
    
    Is this stuff they used to sell, that is loaded with formalhyde?
    

>    Is this stuff they used to sell, that is loaded with formalhyde?
    
No

    I've used it several times for specialized kinds of applications.
    It's not for every caulking job but for others it is just the thing.
    Generally I've used it to fill in gaps (1/4" and up) around the
    sills and foundation.  I once had occasion to fill in around
    window frames, and as noted, it works GREAT for that job.
    
    It's virtually impossible (for me, anyway) to use part of a can
    then re-start it again a day or two later with any kind of success.  
    The nozzle mechanism gets gummed up and just doesn't work.  If you 
    have uses for the foam, save up enough of them so you can use a 
    whole can at one time.
    
    I've also found shelf life to be limited.  Buy it when you need
    it.
    
    Steve
    

    Re: .12:   Are you sure?   I saw some at Grossmans over the weekend.
    It clearly indicated that it was a urea-foam formaldehyde.   It
    recommended that the area filled be sanded and painted.   This is
    typical of the UFFI warnings.   By the way, the stuff I saw was
    manufactured by W.R. Grace.   (The people that recently settled
    out-of-court over chemical disposal suits.)

	I'll second .13 and various others.  If you are going to use it,
	use it all.  Forget about trying to get it out of the can later.
	You might as well throw the remainder in the can away.  Plus,
	wear gloves and old cloths.  Don't drip it on anything that you
	care about either.  What a mess it makes.  Works tho...

	-gary

	don't know if I'd ever buy it again myself....

    I was told not to use it around window frames because as it expands
    to fill the void, it also pushs out on the sides of the window frame.
    As a result. your windows end up sticking and are harder to lift
    up and down. Because I have never used this material myself, I don't
    know if this info is accurate. Can any of you experienced users
    let me in on the real scoop concerning the window sticking problem?
    

    
    I used almost three cans this past weekend (finally) to seal the
    sill and windows downstairs (I just did the tops and bottoms of
    the windows 'cause the sides were stuffed really well).
    
    I used up one, then went to Aubuchon to get two others.  With these
    other two I only used one nozle, this means that I will have a clean
    nozle when I restart the last can (which I did already once - using
    the old nozle with a new tube).  
    
    I thing the one at grossmans does contain formaldehyde, where the
    one from Aubuchon doesn't...
    
    						.dave.

    re: .16
    I can't imagine it would be a problem.  As it expands, the foam just 
    oozes out the hole you squirted it into.  You're also supposed to
    fill the cavities only part full, to allow some expansion space
    (I'm not very good at guessing that - it always oozes out anyway,
    with no discernable ill effects except making a mess).  I suppose 
    if you squirted a lot of foam into a very tiny hole it might push 
    enough to make a window stick...but even then I doubt it.  I can't 
    imagine it would have enough force, unless your window frames are
    made of 1/4" balsa wood or something.
    
    Steve

    How much area can be filled by a can?  Is it cubic inches, or 
    cubic feet, or cubic yards?
    

Weather the foam explands or not depends on the brand you buy.
There were some jobs that I wanted expanding foam and some I
definatly didnt. Its like anything else, read the label.
 I have used the foam in the can many times in my 100+ year old
house. Real good for going after drafts in the cellar and the
foundation. And yes, it does burn, but does not start as easy as
wood. (As a firefighter and product safety engineer I couldnt resist).

Bill

    In response to .18
    
    I can imagine that there could be a problem squirting this stuff
    around windows. I know of a case were it had to be removed afterwards.
    The house in point had, oh, probably 30 windows. All windows got
    a squirt of this stuff, two or three stuck and jammed to the point
    were it had to be removed. 
    

    
    re .19 how much area?
    
    	When doing a small area, more than enough.  When doing a large
    area (many, many gaps), almost enough, but usually some short.
    
    ie, who knows, theoretically you get 100-150 or so feet of 1 inch bead.
    
    						.dave.

Can anyone tell me what is the highest R Value wall practical, that you can see
through, or that would let light into a house? I.E. Windows, glass brick,
Doorwalls, sktlights, etc...  Can you compare those numbers to typical R values
for standard types of walls, and various types of insulation?

I'd like to build a *large* glass skylight, and I'd like to figure out if it
will be practical to heat.  I'd like it if the method of construction lent
itself to large openings for cross ventilation in the summer.

Some idea of costs would be nice too...  (I don't ask for much :-))

Thanks, Jim. 

    Let's see, from memory, not guaranteed.  These can vary some too,
    depending on how well the particular materials are installed, etc.
    
    	Material		R-value
    single-pane glass		.9
    double-pane glass		1.8
    masonary wall		approx. R-1 per foot (!)
    (cement, brick)
    sheetrock			1/inch
    beadboard			4/inch
    styrofoam board		5/inch
    isocyanate			6 or 7/inch
    fiberglass			2.5/inch
    blown cellulose		4/inch
    wood			2/inch
    
    I would *guess* that glass brick would be in the R-2 to R-3 range,
    but it's just a guess.
    Your best bet for a skylight might be double glazing (most of them
    are, I think) with a layer of that reflective mylar tinting stuff
    on the inner surface, or or a skylight made with that new high-E
    glass or whatever it's called.  That might get you up to R-3 or R-4
    by cutting down the infrared loss.

So that means that a normal insulation between 2x4 studs faced with brick
wall would have maybe R 10, adding some for the brick, and subtracting some
because the fiberglass insulation is not continuous...?

Yikes!! It'd be impossible to build up a N pane window to get that good! You'd
need a 11 pane window!

Is this right?

BTW, does the brick facing on a normal wall have *any* advantage over other
facings? I.E. shingles, aluminum siding... 

Jim.

I don't even think an 11 pane window would do it - the amount added by each 
pane goes down as you add more.

And yes, brick has one very significant advantage over most other siding - even 
your grandkids grandkids probably won't have to do any kind of maintenance on 
it.

Paul

    Yup, windows are a BIG source of heat loss.  If they aren't tight and leak
    air, they are an even bigger heat loss.  Which is why calking and
    things like window quilts give you real good return for the $ spent.
    

That kind of trashs the large skylight idea...

What do people with greenhouses do for insulation?

Jim.

    Of course, the other side of the coin is that SOME windows (those
    exposed to some direct sunlight) gain heat during periods as well
    as lose it during others, so whether a large window is in fact a
    loser depends upon how much sunlight it collects and how well you
    deal with the heat gained.
    
    To put some rough numbers on things, an R-3 "low-E" double-pane
    window will lose around 15 BTU/hour per square foot if the outside
    temperature is 25 F. and the inside 70 F.  On the other hand, if
    it's vertical and South-facing it will gain well over 1000 BTU per
    square foot over the course of a sunny winter day, giving you a
    net gain on the order of 900 BTU per square foot over the six-plus
    hours of sunlight.
    
    If the window is shaded (by trees, or whatever) over some portion
    of the day, the gain will be less.  If the window faces more than
    around 20 degrees off due South, the gain will be somewhat less
    (but even SE or SW facing windows should still pull in 600+ BTU
    per square foot if not shaded).
    
    If the window is not vertical but slopes S at about 60 degrees from
    the horizontal, the gain will be slightly more; if about 45 degrees
    from horizontal, it reverts to about the same in December/January,
    but may be better in February/March.
    
    If the area just to the South of the window is reflective (e.g.,
    snow-covered), the gain may be 20% - 30% more - but only if the
    window is vertical.
    
    The main issues are then:
    
    o  What do you do when the sun isn't shining?  (16 - 18 hours per
       day, plus perhaps more on cloudy days)
    
    o  What do you to to prevent OVER-heating (and store the excess
       heat for later) when the sun is out?
    
    If you do nothing to insulate the window additionally, heat will
    merrily continue to migrate out at 15 BTU/hour per square foot
    under the (fairly typical) conditions noted.  Total 24-hour loss
    will be around 360 BTU/square foot.  When you factor in our region's
    average winter sunlight (45% - 50% of potential), you can still
    break considerably better than even with a S-facing window, and
    around even with a SE or SW window.
    
    On the other hand, if you use some additional insulation at night
    (an R-5 shade, an R-10 shutter, or whatever), the potential heat
    gain becomes something worth talking about (assuming that aesthetics
    permit covering the window during much of its non-collecting time).
    
    Additional insulation or not, the heat gain DURING sunny hours must
    be addressed:  there's so much more heat coming in than is going
    out that you'll need some way to moderate the temperature swings
    (well, you could just open the window, but it would be a shame just
    to throw the heat away).
    
    At this point, there's a great deal of literature you could look
    at.  Just didn't like seeing you give up the idea of your window
    out-of-hand based on insulating considerations alone.
    
    		- Bill
    

    One or two other points:
    
    A large skylight could be pure Hell in the summer unless it faces
    North:  the Summer heat gain on an unshaded horizontal, S, E, or
    W-facing surface is LARGE.
    
    However, the Summer heat gain on a VERTICAL S-facing surface is
    not all that bad even without any shading, and can be easily cut
    to almost nothing (in our latitude) with small awnings, etc.
    
    A N-facing skylight, of course, gains no heat in the Winter.  Even
    so, it need not be horrendously expensive.  While the best current
    insulating windows have R-values in the 3 to 4 range (over time
    - some get close to 5, but only until the Argon seeps out), when
    combined with a good insulating shutter (say, R-15) that is closed
    at least 16 hours/day the aggregate R-value gets up into the R-7
    to R-8 area.
    
    Now, in a WELL-insulated house (R-30 or better walls, R-50 or better
    roof), this would dramatically increase heating requirements.  If
    your house's walls are more like R-10, however, the effect should
    not be as pronounced.
    
    (Of course, if you're seriously worried about heat load, you'll
    do something about those walls anyway...)
    
    		- Bill
    

    Re Skylights.
    
    There's a insulating, tracked curtain that guts heat loss and heat
    gain that fits flush with the ceiling. As for windows, we have inside
    storm windows and insulating curtain liners (from Sears) will increase
    the insulating value of curtains.
    
    John Ryan III

Is the scale of R Values normal, or does it have some type of logarithmic
curve?

RE: .7

How do you get R 30 walls and R 50 roof!!!  Are they a couple of feet thick?

Jim.

R values are on a normal scale.  Twice the R value means half the heat loss.

>How do you get R 30 walls and R 50 roof!!!  Are they a couple of feet thick?

There are several ways to get this.  For example the walls in our house are 
built with 2x6 construction and filled with fiberglass, giving an nominal R19, 
and there are 2" of beadboard on the outside, adding another R8, for a total of 
R25 or so, when you count out losses for framing members in the wall.  There 
are many houses built with a double 2x4 wall that's about 10" thick, which 
gives an R30 rating.

Our roof has 15" of fiberglass, for about R45.

Paul

    re -.9
    	Those high R-values are not particularly extraordinary -
    	outside the US.  I have seen references to such numbers as
    	becoming a norm in the northern countries (Scandinavia, etc).
    
    	Also in the true (as opposed to Ma) northern tier states where
    	COLD is defined at 0 and down (deg. F); Minnesota, et al.

    I have a 4 Bedroom contemporary with attached two-car garage. There
    is living space above the garage, mainly part of the master bedroom,
    a dressing area, master bath and two walk-in closets. This area
    is usually much cooler (colder) than the rest of the house because
    it is located above the uninsulated garage. At least this is my
    assumption. The garage wall that attaches to the house and the ceiling
    of the garage are obviously insulated but the two outside walls
    and the front of the garage are just stud walls with no insulation.
    
    Some people in my office are suggesting that insulating the garage
    will not make any difference because a) there is no heat in the
    garage, and b) the garage doors are not tighly weather sealed. My
    thoughts is that it should help, but I don't want to throw my money
    away, either.
    
    Any thoughts on this subject, one way or another?
    						Mike
    

    The garage ceiling (floor of the living space) is insulated?  If
    so, how much?  Did they put the vapor barrier (foil or paper face)
    on TOP, or is it on the garage ceiling side?  If there is less than
    6" of insulation, or if it's put in backwards (vapor barrier down)
    it might be more to the point to fix the ceiling insulation first.

    It would probably help to insulate the garage too.  My aunt and uncle
    owned a house like that and their rooms above the garage were always
    cold.  Insulating might raise the temperature of the garage 5 degrees 
    or so - maybe more - and it all helps.  You might think about 
    weatherstripping the garage doors too.

    
    Insulating the garage won't help (with the possible exception of
    stuffing more into the ceiling - how well is it "obviously insulated"?).
    
    If it's the closets that are cold, expect it. There are no heating
    elements in them, and as soon as the doors are closed, heat leaking
    through the outside walls will cool them off quite a bit.
    
    Otherwise - are you sure there's enough heat getting into that big
    room (especially since it's more exposed than usual by hanging over
    an unheated portion of the house)? What kind of heating system?

    This is sort of on the same topic, but it's a different question.
    I'm about to insulate my unheated basement ceiling.  What methods
    have people used to make the insulation stay up between the joists.
    I have 20 inches BETWEEN my joists. Those wires that they sell for
    this purpose are for 22 1/2 inches between joists.  
    Have you ever tried to cut those wires?  I have.  That's why I'm
    looking for another method.
    
    As for insulating an unheated garage... It will make a difference.
    If the temperature is 50 degrees monday, then goes to 30 degrees
    tuesday, and back to 50 degrees on wednesday, the garage won't
    go down to 30 degrees within one days time if it's been insulated,
    although it might go down almost to 30 if it hasn't been.  All
    insulating does is delay how long it takes for heat to pass thru
    a wall.  If the outdoor temperature is 0 kelvin for a shorter 
    period of time than it takes for ALL the heat in your garage
    to leak out, then the insulation is keeping your garage warm.
    
    Of course, if the temperature is 0 kelvin, you probably won't
    care about your garage.                  

    Re:1
    The ceiling of the garage is insulated, although I can't determine
    if the vapor barrier is on the floor side or garage side. Ceiling
    in garage is finished with plaster so I don't want to poke any holes
    in it.
    
    Re:2
    I think it is at least R-19 in the ceiling. I say that because the
    house is generally well insulated. The dressing area, and dead storage
    are unheated but the closets and bath are heated. We have forced
    hot water, oil fired. Solar panels supply all the heat for our domestic
    hot water.
    

One thing to consider while trying to warm your garage - about the worst 
possible thing for your cars in the winter is a warm garage.  They drive on the 
salted winter roads, and pick up all sorts of ice and salt.  If the car stays 
cold, especially if it stays below freezing, this doesn't do much to the car,
because the cold temperatures inhibit the rusting process.  But if you warm the 
car up, with all that salty guck sticking on the underside, it'll rot out your 
car faster than anything short of driving it on an ocean beach in the summer.

We're building a garage in the spring, and I intend to leave it totally 
uninsulated, to keep it as close to outside temperatures as possible.

Paul

    re .3:  Why not jsut buy 20" insulation (Somerville carries it),
    and staple it in on the sides?
    

    re .3
    The same insulation that keeps the garage from cooling down when
    the temperature drops also keeps it from warming up when the
    temperature rises. Home insulation is not cost effective (or comfort
    effective, for that matter) unless it is preserving heat that is
    intentionally concentrated in the living space.
    
    re .3 and .6
    
    Insulation stapled to the ceiling joists will sag in the middle
    end eventually rip away from the staples. If the wires are not
    convenient, drive smallish common nails into the bottom of
    the joists, leaving the heads out a bit, then run cheap, flexible
    wire across the joists, pulling tightly and wrapping around the nail
    heads as you go.

    About the cold room above the garage:
    
    	Check to see what kind of attic ventilation you have above that
    room.  If the room was an "after thought" there may be *excessive*
    ventilation.  (Running up from the soffits to the peak.  Check for
    vented drip edges at the eaves or holes under the eaves.)  You can't
    get enough ventilation in an "attic space" but for living space
    too much will leave you cold...
    
    					Don Arey

    The attic above is well insulated. There is a pull-down stair in
    that room that provides access to the attic. That may be a vunerable
    area. The builder built a insulted box that should fit over the
    opening, but it doesn't because the stair mechanism takes too much
    space. Any hints on insulating pull-down stairs????
    

    When we moved into our house in Colorado Springs, we toyed with
    the idea of installing the insulation ourselves. We found that with
    the purchase of the rolls of Corning insulation, the price for the
    blown-in by a contractor was within $75.00 for a 1700 sq ft tri
    level with about 1400 sq ft of attic space (including garage). 
          
    The house was built in 1973 so it had the thermal insulating board
    as well as the normal roll (paper backed) insulation. We were told
    that if we want more insulation, they could cut 1" dia holes under
    the eves and blow the insulation in.
    
    As for finding the fire stops, use a stud finder on the inside walls
    and locate where the studs. Most studs are 16" to 24" centers but
    be awear that the corners and around windows, there will be double
    studding or irregular studs. We have a stud finder from Sears for
    under $20.00.
    
    /cal hoe

    The attic in my house has blown in fiberglass insulation. Unfortunately
    the jerk who installed it didn't put enough in to fill the spaces
    between the joists. I want to bring it up level with the joists
    but nobody seems to sell loose fiberglass insulation. It seems my
    only option is to call a contractor to top it off.
    
    Does anyone have a better idea?
    
    - Rich

    
    re .2
    
    Loose, blown-in fiberglas? Sounds like an invitation to permanent
    lung damage. I get itchy just thinking about it.
    
    How about laying unfaced fiberglas batts over whatever is there
    already? You lay it parallel to the joists to bring the insulation
    up to the joist tops; if you add more than that, lay it across the
    joists for maximum insulation.
    
    Alternatively, you could add some cellulose blown-in (which, if
    I had to put money on it, is what I would guess you already have
    up there). If you buy that stuff from Grossman's, you can borrow
    the application machinery for free.
    
    Whatever you add, be careful not to block the soffit vents.

    If you can get at the attic use roll fiberglass. As far as the
    walls are concerned you can rent a machine that will blow in
    cellulose. 
    
    I had mine done about 13 years ago with cellulose by a contractor.
    If I did it today I'd still use a contractor.
    
    re:2 
    You can get the cellulose in bags if you want to top off your
    attic.

Re: .3

I just put up ceiling insulation where the joist size varied (some of the 
joised had been doubled up for strength). I just curved the "wires" - worked 
fine. Not as pretty as putting them up in their intended space, tho.

The wires are great if you're truely DIYing, i.e. installing insulation without 
any help. You can push the batt into the space, hold it with one hand, and 
install the wire with the other.

-scott

    I need some information on the wrap they use on the outside of
    houses underneath the siding. I believe it is usually installed
    in new construction before the windows are put in, but how much
    of an extra effort is required if it is done after the windows
    are in. The information I need is: Hoe expensive is the material
    itself, and how much is the labor $ to install it. I do not
    know the exact dimensions of the house but it is a Garrison
    Colonial with a 22 by 24 ft family room over a double garage on
    the end. I belive the foundation is 26 by 36. Any estimates or
    ball park figures would be appreciated. Also , I would like some
    feedback on how beneficial this wrap is, i.e. does it return its
    investment in a reasonable amount of time.

    The stuff you're talking about is Tyvek (spell).  In my house it
    was put on AFTER the windows were installed.  The windows, as a
    result, are cold.  If I had it to do over again (and I just might)
    I'd put it on first to ensure that the windows wouldn't leak so
    bad.  
    
    
    				KO

    Devil's advocate for the moment:
    Since virtually all houses are sheathed in plywood these days, I
    have trouble understanding the need for this stuff.  It will seal
    the joints between sheets of plywood (of which there are relatively
    few, compared to the total wall area) but what else does it do for
    you?  Plywood goes right to the edge of the rough window openings;
    any gaps around windows will be between the rough openings and the
    finished frame, and this stuff won't help you there, those cracks
    need to be calked anyway.
    People used to use rosin-coated building paper (relatively cheap)
    before this new high-tech stuff (relatively expensive) came along.  
    I'm not sure the extra bucks buy you anything worth having.  But
    I may be missing something here.

    The trick in today's house building is to eliminate those relatively
    few joints between the sheets of plywood in order to get a tight
    house.  Rosin paper comes in rolls about 3 feet wide.  Tyvek comes
    in rolls 8 feet wide.  The idea is to have as few seams as possible
    from any wrap.
    
    Just imagine having a 1/16 inch crack where a double hung window
    meets the frame of the window.  Although the 1/16 inch is relatively
    small area compared to the total window area, alot of heat can be
    lost thru it.
    
    -al

  I saw Tyvek used on "This Old House" this weekend.  They claim that it does
  an excellent job of stopping air infiltration.  My neighbor, who works in
  construction, says that they use the stuff all the time these days.

  The question is, do you *want* to stop air infiltration, given the current
  worries about radon and the "cabin fever" syndrome caused by combustion
  products.  I wouldn't use the stuff if I were going to use a woodstove
  in the house.  I might not use it in a house built on a slab...

  JP

    Relative to price, last time I used it the cost was about $1 a running
    foot (standard width is 9 ft).  At that price a 24x40 two story
    home would run $256.  But I wouldn't be surprised if it wasn't more
    now.  It's used in virtually all construction these days and I think
    that Dupont still holds the patent and hence the exclusive
    manufacturing rights.
    

RE .4
    That's a good question, do you want to stop air infiltration? If
    you are planning to do nothing to improve the quality of air in
    a tightly sealed (energy efficient) home then perhaps it's best
    to pay higher heating bills and let it leak. However, there are
    many makers of AIR to AIR exchangers on the market today that will
    allow you to tightly seal your house, and keep the air fresh. I
    installed a model by NUTONE the AE200 and am very satisfied with
    the results and efficientcy of the unit.
    
    							Dave
    

    We live in an energy efficient condo, which is wrapped and the outside
    of the condo isn't plywood but energy shields.
    
    So it goes like this from the outside:  siding
                                            energy shield
                                            wrap (I don't know what
                                                  kind)
                                            Drywall
    
    We have an air exchange and a heat pump.  I recommend the air exchanger
    anyway as we don't worry about "radon," so prevalent in NH, and
    smoke from the stove, etc., goes out quickly.
    
    We were told when we bought the condo that if the air exchanger
    was not working we were to leave a window open a crack in order
    to prevent the buildup (I think, but not sure) of CO2.  Does that
    make sense?
    
     

    	They make great cleanroom bunny-suits  (and are they ever expensive!)
    
    	So... it'll keep dust out of your house too!  :->
         
    					Don Arey

    The 8' wide rolls of Tyvek I saw at Somerville (good store, but
    ever notice how much time you spend just standing around while the
    clerks key in a $2.50 order?) the other day were around $150.  They
    also had 4' rolls.  Both were 100' lengths.
    
    I've never been convinced of the cost effectiveness of Tyvek.  I
    went through the process of thinking it out when planning the addition
    I'm putting up.  If you want a *toasty* house as opposed to a *tight*
    house, then skip the Tyvek, use 6" walls instead of 4" (it'l cost
    not that much more, and be sturdy to boot), and wrap the *inside*
    with plastic.  Not only do you save the cost ofthe Tyvek, but the
    insullation is cheaper because you can use unfaced.  The plastic
    (4 mil minimum) will be a much better vapor barrier than the usual
    facing, because you just stretch it over everything (studs, windows,
    outlets) and then cut out just what is necessary (over the windows
    and outlets).
    
    When I was discussing this with the framer (who had no $ stake in
    the decision) who also builds entire homes, he said pretty much
    the above.
    
    fyi,-reed
    

    It is standard practice to use unfaced insulation and the 4 mil poly
    as a vapor barrier.  Tyvek is not a vapor barrier, neither is rosin
    paper.  You wouldn't want a vapor barrier on both sides of an insulated
    cavity.  Tyvek provides an effective air barrier yet lets water
    vapor thru, kind of like Gortex.  I would consider a builder who
    uses Tyvek to be energy conscious and one who gives the extra effort.
    
    -al

This stuff stops air, but lets water through???  Sounds incredulous to me! Oh
well, I guess that's Hi Tech...  Why would you want to let water through, in any
case??

The use I've heard of Tyvek is mailing envelopes.  They are supposed to be
stronger, lighter, expensive, but you make up the expense of the envelope on the
decreased mailing costs.  Can't say I understood how it could make a real big
difference. 

Jim. 

>This stuff stops air, but lets water through???  Sounds incredulous to
    me! 
    The Tyvek on my house is watertight.  It holds water like a plastic
    bag.
    

    Tyvek is airtight but VAPOR permeable.  That is not the same as
    not watertight.  As mentioned earlier, if you put a vapor barrier
    on both sides of an exterior wall, you will guarantee condensation
    of trapped vapor at low temperatures with resulting insulation and
    wood rot over time.
    

    I was under the impression that it was *water* resistant, but
    not *moisture* resistant.  Like gortex it will allow your house
    to sweat, yet still act as a wind and water break.
    
    You want the moisture in the house to sweat out so that it does
    not condense into water in your insulation and structural wood.
    Wet insulation may not insulate as well. Wet wood rots.

Interesting duscussion...

A while back when I built an addition I called Owens/Corning customer 
services and talked for around 1/2 hour with one of their engineers.  
What he told me has me real concerned around this whole subject.

As said earlier, the idea is to prevent water vapor from being trapped 
inside the wall cavity.  Gortex is truely waterproof but allows body 
sweat to pass through.  I suspect Tyvek does the same thing.

Now for the problem.  Interior walls are NOT waterproof.  Moisture will 
indeed pass through.  Faced insulation still has cracks where it meets 
the wall joists or where it's cut out for pipes, wires or anything else.
However, as long as the porosity of the exterior wall is greater than 
the interior wall, any moisture that gets into the cavity will have a 
reasonable chance of passing clear through.  In fact, in the old days 
before plywoods, exterior walls were extremely efficient at passing 
mosture through.  The big problem that plywood introduced is that glue 
is waterproof and will only allow moisture to pass through where it 
meets another piece.  He went on to say that he's seen houses that 
didn't breath had joists rot out in 5-10 years!  Another VERY strong 
case for letting you attic breats a LOT!

So, what to do?  Exactly what an earlier note said.  Use unfaced 
insulation and cover it with a sheet of polyethylene.  This will give a 
very watertight inside and very little moisture will get in.  Any that 
does will surely get back out.

My particular interest in this whole thing cenetered around cathedral 
ceilings and how to insulate them.  You MUST leave an air cavity above 
the insulation (if using fiberglass) and provide vents at both the top 
and bottom to allow air to flow over it and carry the moisture away.

So what then does Tyvek do?  No idea, but it sure look pretty!  
Seriously, I'm sure it does some good, but I just haven't heard a good 
explanation of it yet.

-mark

    I'm the process of building a family room addition onto our house.
    I wrapped the outside in Tyvek mainly to protect the outside of
    the structure.  (I Wasn't sure if I was going to get the vinyl siding
    up before the weather got really awful.)  I was also pleased to
    find out that (in researching) that the Tyvek is "waterproof" but
    not moisture proof.

    BTW, I also turns out that, at least in Hudson NH, having the house
    wrap and windows in is complete enough to allow the building inspector
    to do the framing inspection.
    
    When done, the walls will consist of:
    
    	Vinyl siding
    	1/2 CDX plywood
    	Kraft backed fiberglass insulation
    	6 mil poly vapor barrier
    	1/6 T&G redwood cedar
    
    The main reason for the cedar and poly is that the family room will
    have a 5 person spa in it.  With the (removable) top off, there
    will be a fair amount of moisture in the air.  This is somewhat
    countered by the fact that the room is about 5200 cu.ft. (19' x
    24' with a 8' to 14' vaulted ceiling).
    
    I may yet have to put in some additional means of venting the interior
    moisture (beyond the soffit (sp?) and ridge vents).
    
    - Mark

>        	1/6 T&G redwood cedar

 What's that?
    

    Redwood cedar is red cedar vs. white cedar vs aromatic cedar.
    
    -al

    Oops.  Should have been 1x6 not 1/6.  The fingers slipped.
    
    As noted in .-1, I indicated redwood cedar to distinguish it from
    the more common lighter shade crdar.
    
    BTW, I'm really looking forward to putting it up (at least sawing
    it), it smells great.
    
    - Mark

    We have 6" of fiberglass in the attic.  We'd like to increase that
    to a total of 12", or even more if we have the money and if we can
    get it to fit.
    
    An energy contractor recommended against putting up additional
    fiberglass, and instead recommended that we put in blown cellulose on
    top of the existing fiberglassbatts.  (Not surprisingly, he happens to
    do blown cellulose insulation.)  The reasons he cited were: 
    
    	1) Cellulose is less sensitive to moisture than is fiberglass.
    	   I.e., it doesn't lose its insulating ability as fast as
    	   fiberglass does with increasing moisture.
    
	2) It can fill in little crevices in the corners, edges, etc. of our
           attic.  Laying additional fiberglass down will "inevitably"
           leave holes in the insulation layers. 
    
    	3) Cellulose is less sensitive to air moving through the attic.
    	   Quote: "When air moves through your attic via the attic vents,
    	   the fiberglass can't do its job, whereas the cellulose still
    	   can.  Fiberglass needs still air to do its job, and cellulose
    	   doesn't."
    

    Reason #3 sounds like a crock, #2 sounds plausible, and I have no idea
    how to gauge #1.  Can anyone share some information and advice on the
    relative merits of cellulose vs. fiberglass?
    
    jdr 

IF you don't have a vapor barrier, and you have existing blown
insulation, you cannot use rolled fiberglass unless you remove all the
existing insulation (very difficult) AND use the more expensive
fiberglas bats that have a built in vapor barrier, because fiberglass
WILL absorb moisture, thus decreasing its R Value. 

Blown celluose has the following advantages:
1) More R value per inch (2.7 vs 2.3 for fiberglas)
2) impervious to moisture
3) totally non-flammable
4) can be installed over blown insulation.

Of course, once its there, its hard to use your attic for storage.

    I don't see why fibergalss batts would be any more prone to moisture
    absorbtion than cellulose, assuming it is in a "dry" place (i.e.
    water isn't dripping on it).  Use unfaced fiberglass batts, and
    water vapor ought to go through, and evaporate from, the fiberglass
    just as well as from cellulose.  Cellulose insulation is, after
    all, just pulverized newspaper.
    
    My personal choice would be unfaced fiberglass batts, on top of
    the existing insulation between the joists if there is still space
    there, or at right angles to the joists if the space between is
    already filled.
    You'll need good attic ventilation, of course, because with no vapor
    barrier the idea is for the water vaopr to pass through the insulation
    and out the top surface into the attic space.
    

re .0

	1) Wouldn't believe it without documented proof from an impartial
	   insulation-testing laboratory.

	2) Good point, but the "inevitability" of gaps in fiberglass insulation
	   is inversely related to your level of patience. The same can probably
	   be said for the installation od cellulose.

	3) A crock. In fact, as air movement increases, I would trust
	   the structural integrity (and thus the insulating value) of
	   interlocked strands of fiberglass, over a lot of loose pieces
	   of paper.

re .1

	The first statement seems to assume that the additional fiberglass
	insulation would have an integral vapor barrier, which is not usual
	or reccomended for such add-in installations. A fair comparison of
	the two products relative to adding insulation to the attic, should
	assume that neither add-in product has an integral vapor barrier.
	With that assumption made, the question of whether a vapor barrier
	exists under the present insulation is not significant to the
	comparison of products.

	Regarding the stated advantages of cellulose:
	1) Good!
	2) Any insulation will collect water on its surfaces if moist air
	   is allowed to cool as it passes through the insulation. Vapor
	   barriers are impervious - cellulose and fiberglass are not.
	3) so is fiberglass
	4) so can unfaced fiberglass

Question - is there any truth to the rumor that cellulose insulation has a
tendency to settle? (This would decrease its insulating value over time.)

    rep: .0 .3
    
    	.3
>    3) A crock. In fact, as air movement increases, I would trust
>   	the structural integrity (and thus the insulating value) of
>   	interlocked strands of fiberglass, over a lot of loose pieces
>   	of paper.
     
    Well, it's now exactly loose pieces of paper.  It's GROUND up
    newspaper, much more like pulp, not piecec of paper.
    
> Question - is there any truth to the rumor that cellulose insulation has a
> tendency to settle? (This would decrease its insulating value over time.)
    
    This is not a rumor.  I was up in my attic yesterday doing some
    wire routing and I can attest that cellulose DOES settle.  Not only
    does it settle, but it settles quite a bit.  I blew in about 8"
    or so of cellulose about 5-6 years ago and it's now down to about
    6" (I don't remember how much I put in originally and I didn't take
    a ruler up there to measure the height now, so there are guesses).
    
    .0
    
    3.  Not necessarily a crock. Since cellulose does settle, I think it
    would be less prone, NO I know it would be less prone to be "windblown"
    than Fiberglas, 'cause I've been up there in the summer before
    I added the cellulose and there was always Fiberglas visible in the air.
    Now that the cellulose has settled, it doesn't seem to be airborne
    anymore.
    
    -Bob 
                                               

.0>    	3) Cellulose is less sensitive to air moving through the attic.
.0>    	   Quote: "When air moves through your attic via the attic vents,
.0>    	   the fiberglass can't do its job, whereas the cellulose still
.0>    	   can.  Fiberglass needs still air to do its job, and cellulose
.0>    	   doesn't."
    
.3>	3) A crock. In fact, as air movement increases, I would trust
.3>	   the structural integrity (and thus the insulating value) of
.3>	   interlocked strands of fiberglass, over a lot of loose pieces
.3>	   of paper.

.4>    3.  Not necessarily a crock. Since cellulose does settle, I think it
.4>    would be less prone, NO I know it would be less prone to be "windblown"
.4>    than Fiberglas, 'cause I've been up there in the summer before
.4>    I added the cellulose and there was always Fiberglas visible in the air.
.4>    Now that the cellulose has settled, it doesn't seem to be airborne
.4>    anymore.
    
    In .0, the contractor seems to imply that normal and desirable air movement
    in the attic somehow decreases the insulating value of a layer of fiberglas,
    while having no effect on a layer of cellulose. Conversely, she may be
    implying that cellulose can preserve heat while allowing air to blow through
    it, and that fiberglas cannot. In any case, she is laying out a steady
    stream of cow flop.

    Thermal insulations work by immobilizing a layer of air to slow the
    migration of heat from one place to another. Air movement outside the
    the blanket has no bearing on whether the blanket can hold onto the air it
    has trapped. All insulating blankets are affected in the same manner by
    adjacent moving air (assuming the the blanket has the structural integrity
    to hold fast against the air current). No insulating blanket can arrest heat
    flow while allowing air to flow through it.

    In short, the only credible advantage of cellulose, among those stated
    so far, is that it provides more insulating value per inch than fiberglas.
    

< Note 774.0 by ELGAR::DEROSA "I (doghead) heart bumper stickers." >
                      -< Blown Cellulose vs. Fiberglass >-

>    We have 6" of fiberglass in the attic.  We'd like to increase that
>    to a total of 12", or even more if we have the money and if we can
>    get it to fit.
>    
>    An energy contractor recommended against putting up additional
>    fiberglass, and instead recommended that we put in blown cellulose on


	There's only one way to do this one.  Just add more fiberglass
	bats.  Because you have alot of space in the attic, unlike walls,
	you can add another 6" to give you R-38 which is great.  The difference
	between cellulose and that is insignificant.

	I blew cellulose into our _walls_, and it's working just fine.
	(Read the earlier notes in this file about the cellulose 
	controversy).  However, it is messy and in fact _less_ rugged
	than fiberglass _more_ susceptible to moisture damage (this is obvious)
	and probably a little more prone to fire, although I took a 
	hand full of the stuff and held it over a flame, and it doesn't
	burn.  A true _full_service_ insulation contractor would have
	a choice between cellulose and Fiberglas for different applications.
	
	Your attic is well ventilated (?) so moisture condensate is not
	much of a problem.  If you've got 6" up there, it probably has
	a vapor barrier on the bottom side next to the ceiling.  If not,
	the very large ventilation area you should have up there will
	allow the transmission of moisture out of the insulation and you
	won't see any results of condensation both within the insulation
	and on the roof sheathing.  If you're real concerned about this,
	buy some Glidden vapor barrier paint (they seem to be the only
	one's who make it) and repaint your ceilings.  However, I don't
	think that this is necessary.  For the walls in the house, since
	their cavities can be very tight if you've got plywood or particle
	board on the outside, diffusion of moisture to the outside is
	much more critical, and a good vapor barrier inside will reduce
	the amount of water vapor getting into the walls.

	Buy the Fiberglas and just unroll it up there yourself!

	/Charlie

    I just have one question for the cellulose proponents: 
    If you add an additional four to six inches of cellulose to a six
    inch fiberglass base, how on earth do you ever get around in your
    attic without smashing down the cellulose (and thereby destroying
    it as insulation)? I am sure that the total inches 10-12 will 
    extend above the average ceiling joist. At least with the fiberglass
    batts I can pick them up and move them around.

A couple of questions...

I am remodeling an existing addition to my house. It has three outside walls 
one story, and a pitched roof. It is 13 x 15.  It had some water damage 
(bad roof that has since been fixed) and after removing the wall and ceiling 
panels the insulation looks like it was exposed to water. My question, does 
the R value change after insulation gets wet? If so should I remove/replace 
it or add more ? 

Another question - After I get my insulation straightened out should I install
a vapor barrier ? If so should I do the walls/ceiling or both ? The room seemed
to be a "cold" room before and was just used for storage, now it will be the
Master bedroom and I want to make sure that it is tight and warm.

              Any suggestions/comments would be appreciated.

    The R value is reduced when the insulation is wet, but unless it
    as been compacted it returns to its original value when it dries.
    The vapor barrier isnt necessary if the insulation is backed (paper
    or foil) and if it is properly installed. Installing a plastic vapor
    barrier on the inside - next to the drywall - makes installing the
    drywall a little tricky since it tends to slide a lot. Do not try
    to install it on the other side of the insulation since it will
    trap the moisture in the insulation and reduce the R value.
    The most important place for good insulation is in the ceiling where
    it should be a minimum of 19 . R 35 (9 inch) is preferred for New
    England.
    

    
    I just bought a townhome that's about 20 years old and needs a lot
    of work.  One of the things that I was not aware of is that there
    is no firewall between my  unit and the ajoining unit.  Because
    of this, the units are not sound proof by any means.
    
    I figured that most of the noise could be muffled if I blew some
    type of insulation between the two wall - since there doen't seem
    to be any.  Does anyone know if insulation will muffle the sound?
    Does anyone know of any special type of insulation that I should
    be looking for?
    
    -Ted Salem
    
    (a townhome-buying tip: don't buy a place unless it has a firewall.
    foutunately, I have a quiet neighbor but a loud one would drive
    me crazy.  Next time I'll know better.)
    
    

That 'space' between the inter-unit walls is probably common property.  
You might want to checkwith your association before you fill it

    Using .2's suggestion, add a new wall using 2x2's and insulation
    infront of the wall on your side of the condo will help reduce sound
    conduction. Be sure the 2x2's are not in contact with the original
    wall.
    
    /cal

    I did EXACTLY what .2 described with the addition of a couple of
    4X8 ft. sheets of a material called 'sound board'. perhaps thats
    just what the lumber yard called it. But this was applied to the
    studded wall just before the blueboard went up.  I  did this on
    the wall of my bedroom where the shower stall was on the other side.
    
    One more important note: I recall (prior to doing what i did) reading
    a book that described sound proofing the walls. The illustrations
    showed a good, better, best design....where the best design indicated
    that the double wall (sound deadening wall) was actually made up
    of 2 'independant' walls designed like that in (.2), with the studs
    staggered....except that the top plates & sole plates for each wall
    were independant of one another. This design was said to be superior
    as no noise/vibration could be 'coupled' from one wall to the other 
    through the top & bottom plates.

    MArk

    
    re .4:
    
    Yes, I remember getting the idea from a paparback govt. publication
    on home construction. I recall dismissing the necessity of the separate
    plates, because even they are coupled by being attached to the ceiling,
    and because the common 2x4 plate gave maximum decoupling with minimum
    wall depth.

    Even just putting another layer of sheetrock over the wall could
    help tremendously.  
    
    From my reading of a similar article, the two important
    characteristics for sound-proofed walls are decoupling and mass.

        You can get decoupling from either staggered stud walls *or*
    using something called "z-channel" strapping.  The "z-channel"
    is a long strip of z-shaped metal:
    
    
       ___________________  ~______________
      /                    ~              /\____ 
     /___________________ ~______________/  \  /
         \______________ ~___________________\/    
                        ~
    
    You nail it up like furring strips, then screw the sheetrock to
    the channel.  The channel provides the decoupling (for a lot less
    expense and aggravation than reframing the wall.

    Doubling up on sheetrock will give you added mass.  A recent letter
    to FHB recommended layering two different thickness sheetrock
    (e.g. 3/8" over 5/8" rather than 1/2" over 1/2") to take advantage
    of the different resonance frequencies associated with each thickness.
    
    You could easily attach z-channel over your current sheetrock and
    attach a new layer of 5/8" (the current wall is probably no more
    than 1/2").  A little joint compound and paint and you can relax
    in peace and silence.
    
    bd
    
    
        

    Well, we're coming down the stretch and I'd like to take this
    opportunity to mention some ideas that I'll be including in the
    contract to see if you people can find any mistakes I've made.
    
    Everything's clear except that I want to be sure that the resulting
    cathedral ceiling is insulated as much as possible.  I plan on
    specifying that the contractor make sure that "proper vents" and
    installed between each rafter and run the whole distance from the
    soffit vents to the ridge vent, and that unfaced insulation plus
    a poly vapor barrier will be installed to give me max R-value (i
    don't know what this is because I don't know whether I'll find 2x6's
    up there or 2x8's or what, but I want max R-value.  Should I also
    require rigid insulation and if so, where does that go?  On the
    ceiling side of the rafter or atop the roof under the shingles?
    
    Thanks for any feedback.
    
    Pete

  I think you objective of getting the max amount of insulating value
in your cathedral is the right idea. I was received some information
from the Mass Save people when I had an audit done on my house. One o
the interesting points mentioned about insulation was that most of the
insulating (80%) is done by the first 20% to 40% of the insulation
installed. What this means is that adding insulation later on yields
minimal results. So the idea is to put in as much insulation as is
possible in the beginning.

  In addition I would also include in your design a ceiling fan to
force the heat collecting in the cathedral back down into the
living space. In the summer if you don't have central air you can
reverse the fan to remove the heat.

  One last thing. The spacers to provide air circulation between the
insulation and the roof is critical to avoiding moisture buildup that
will soak the insulation and reduce its R-value.

Good Luck.
Pat

    I am doing an addition and have a short section of roof,about 4
    feet, that I will have to insulate in the rafters. instead of 
    propervent which is just bead styrofoam, I was going to put straping
    against each side of the rafter to make the air gap, then nail/staple
    rigid foam insulation, or the 1/2 inch foil backed then use possibly
    the pink rolled stuff...Have to figure out what will give the best
    R value in the space, not too concerned over $$. Just an idea ,the
    proper vent doesn't add much in R and isn't too cheap itself...
    Jean
    

    But will that rigid styrofoam act as a vapor barrier and not allow
    the moisture that may be in the insulation to be carried away by
    the air flow on the other side of the styro?  I ask because styrofoam
    coffeecups seem to be pretty effective vapor barriers.
    
    Pete

    that is very likely, I was figuring the first vapor barrier would
    stop it , but I'm sure some gets thru, probably should use all
    rigid foam insulation... Mine isn't too bad, it's only a 4 foot
    section at the biginning of the wall up to where a flatter ceiling
    starts that has more open area above it, so any moisture should
    be able to escape up there under the short piece of rigid foam
    and pink insulatin....
    
    				/\
    			      /    \
    			    /	     \
    			  /	       \
    			/**************  \
    		      /-----------------*\ \
    		      |			 *\ \
    		      |			  *\ \  * = pink insulation...
    
    		      |			   | ^= vent space
    		      |			   |
    
                                                          
    It may not be good with pink and rigid outside of it all the way
    up like you said...
    						
                                        
    Jean

    Talked with the builder last night and the plan is to have 2x12
    rafters between the roof and ceiling, so if I install 9" of insulation
    there'll be about 3" of air space between it and the roof for air
    circulation.  There'll be soffit vents and a ridge vent so everything
    should be OK.  I'm not sure that the added expense of 2 or 3 more
    inches of insulation and Proper vents will pay off.
    
    What about installing rigid foam against the roof, so a cross-section
    would look like this:
    
    
         /-roof
        //-rigid insulation
       //o-air space
      //o==-pink insulation
     //o==/-ceiling
    //o==/

I don't think the rigid foam against the roof is a very good idea.  If your 
ventilation works correctly, then the air in the air space should be (almost) 
constantly moving, and thus pretty much at outside temperature.  Insulation 
between this air space and the roof surface is sort of like insulating the 
outside from the outside - I doubt it'll do you much good, if it does any at 
all.

If you are thinking about rigid insulation, nail it to the bottom of the 
rafters after putting in the fiberglass and before the finished ceiling.  If 
you use the foil-faced stuff, you can get your vapor barrier by this method 
also.

Paul

    re: .6
    
    Good point.  Thanks!

    The September issue of Practical Homeowner (p84) identifies "6 brands
    of thin plastic sheeting designed to stop air infiltration into
    exterior walls, reducing drafts and lowering heating and cooling
    costs."
    
    They are:
    
    	Tyvek, Barricade Building Wrap, Airtight-Wrap, Rufco-Wrap, Tu
    Tuf Air Seal, and Versa-Wrap.  The article (1/2 page) gives addresses
    one can write to for detailed descriptions.
    
    AS far as current pricing I saw where P. F. O'Connor in Merrimack
    NH is selling a 9' x 175' roll of Tyvek for $119.
    
    

I read all the notes on refinishing basements, but I really haven't answered
any of my questions yet.

I haven't decided yet if I should do my basement in foam (i.e. Thermax or
styrofoam) or go with the studded walls and insulate.  The house is less than
two years old and we want to finish the basement off with a family room and 
rec room.  I was planning on putting up a studded wall through the center of 
the basement to separate the utility and work areas.  But is this necessary 
around the entire perimeter of the basement.  The foam can go up quick and easy 
with some panel adhesive.  That way I can get my basement walls insulated right 
away and not be messing around with wood all summer and fall.  With a jagged 
studded wall down the center of basement, I can make all my electrical drops 
to compensate both sides therefore getting electricity for both the family/rec 
room and the work bench/utility area.

What's the price up putting up a studded wall and insulating around the basement
walls compared to an equivalent R rating of foam.  I've heard that Thermax (an
energy shield) is pretty good (R7.5 per inch), but at $22 a 4x8 sheet of 2 inch,
it can get quite expensive.  Are there any other kinds of foam available at 
lower price or something that I can get the equivalent R rating of studded 
insulated walls.

What are some problems I might have with the foam in the future.  I read one
note about the dangers of a fire with it.  Will sheetrock cemented on the foam
keep any fire from reaching it?

Has anyone else given this any thought?  Should you always stay with studded
insulated walls?  Is the foam a great new time saving concept on insulating
basement walls?  Should I sell my house and buy one with a finished basement?
Should I get my head examined?
Thank you for your support,
Mike_L

    Mike, there's an article in the March '87 Practical Homeowner that
    should answer every question you asked.  It's too detailed to type
    it all here but I can send you/anyone else a copy.
    
    John

    Don't forget that you'll need electric outlets all the way around that
    room, NOT just on the dividing wall. The foam walls will complicate the
    wiring of those walls. Personally, I would stud, wire, insulate and
    sheetrock the walls. 
    
    Charly

    There's some other notes on this subject in here, somewhere.  2"
    extruded styrofoam is about $10 for a 2'x8' sheet, and is about
    R10.  I'd go with that instead of Thermax, myself; the foil faces
    of Thermax really need to be facing a dead air space to work well,
    and if you're gluing the panels to the concrete and glue sheetrock
    to the foam you've lost all your dead air space.
    You do need 1/2" sheetrock covering to meet firecode.
    I did this about three years ago (glued strofoam to the concrete,
    and sheetrock to the foam), and it's worked fine.  I used 1"; if
    I were doing it again I'd use 2".  You can use Wiremold surface
    wiring if you need outlets around the outside walls.
    

>    2" extruded styrofoam is about $10 for a 2'x8' sheet, and is about
>    R10.  

That's really only $2 cheaper per 4x8 section than Thermax, and I think the 
Thermax has significantly better insulating value, even ignoring the foil.  The 
extruded styrofoam is best used somewhere where it's going to get wet - like on 
the outside of the foundation or under a slab, where the Thermax will get 
soaked and useless.  The one other option is expanded styrofoam, otherwise 
known as beadboard.  That's only about $10 for a 2"x4'x8' sheet, which is about 
R8.  It's by far the cheapest board insulation, and it works perfectly well in 
applications where it's not going to get wet, and where thickness is not an 
issue (It's twice as thick as Thermax of equivalent insulating value.)

Paul

    re .3
    Yes, I saw your note on "if you were to do it again, you would have
    it done in 2 inch."  Do you think that the Thermax will lose some
    of its R value because of no dead air space?  At 7.4 per inch, that's
    higher than the extruded styrofoam.
    
    Although the foam will be easier and quicker to install, What would
    a 4x8 section of a studded wall with the 3 1/2 inches of isulation
    roughly cost since a 4x8 section of Thermax or Styrofoam is going
    to be about $20?  Or would it be easier to calculate a 8x8 section
    since that's the wood length?
    
    Thanks for all the input so far.
    Mike_L

    Re. Comparable costs for a stud wall...
    
    Probably about $10 for a 4 X 8 foot section.
    
    Charly 

    A stud wall and fiberglass is definitely the cheapest way to go.
    Not necessarily the easiest.  Glueing up foam and sheetrock is
    trivial.  
    I view that R7.4 number with some suspicion.  They may measure that
    in a laboratory; in the "real world" I have my doubts, especially
    if the foil faces are in a situation where they are not doing much.
    The R5 for the Styrofoam is also a laboratory number, of course,
    but my hunch based on absolutely nothing at all is that it may be
    more achievable in real installations.
    Basements get wet,or at least damp; that's one reason I went with
    the Styrofoam.  "Beadboard" has virtually zero strength; you can't
    use the "glue the sheetrock to the foam" trick with it, you'd need
    to put up strapping or something to attach the sheetrock to.  By the 
    time you go to all that trouble you've probably eaten up in time any 
    cost savings in materials.
    Styrofoam also gives off slightly less lethal fumes in a fire, I've
    been told, than the Thermax stuff.

     I checked the notes about insulation and didn't find an exact one for
     my problem (if there is one please point to it) so here goes. 
                    
     I have a 10X10 closed-in porch with hot water baseboard heat. It has
     many windows and a southern exposure so it can be quite nice on a
     sunny spring or fall day. The porch is suspended with concrete blocks
     at the far corners and centers of the outside walls. The area under
     the porch (about 2 ft high) is open to outside air because of vertical
     1X3s between the blocks. 
                                                              
     The problems is no insulation under the porch floor! The previous
     owner had put some cheap wood around  the 1X3s in an attempt to keep
     the cold out. I took off the bad wood this spring to let the crawl
     space air out, but now I need to insulate the floor. 
     
     What is the easiest/best insulation to install under there given the
     exposure to outside winter temperatures and a dirt floor?
     I want easy (fast) because I don't want to crawl around under there
     at all (about two thousand spiders I presume ;-}).  Also, should
     I try to seal off the area for the winter after I install insulation?
     Other notes in this file suggest that. If so what is a reasonable
     way to seal and unseal by season.
     
     Thanks for you help,
     Dave

    I would put in the fibreglass mats for the max thickness i could
    fit between the 1x3's(?). You don't say what the spacing is so
    I assume 16'oc. Use unfaced and then cover with 4mil poly, or 
    use the faced insulation and staple to the 1x3's.
    
    The other alternative, is to build walls around the perimiter
    and insulate them. I believe you said the height was two feet.
    This will mean, however that you are heating the ground under 
    the porch, some heat will escape through the floor. If you 
    insulate the floor you will only be paying for enough heat
    to heat the room and not the dirt, and spiders, under the porch.
    
    my $.02 worth
    

    The correct method as seen on this old house (yesterday as a matter
    of fact) is to install 6" thick faced insulation between the joists
    with the kraft or foil TOWARDS THE HEATED AREA.  Installing from
    below you will be looking at pink stuff.  Hold this in place with
    the pieces of wire sold for the purpose.  I forget what they are
    called.
    
    Before you do this you need to put plastic 6 mil  or heavier on
    the dirt beneath the porch.  This makes it easier to crawl around
    and prevents dampness from going up into the porch.
    
    You gots to get in there with the spiders to do it right.  I'd go
    in with my shop vac in front of me to suck the buggers up first.

     Thanks for the info. The plastic sounds like a nice idea.
     
     Dave

I have been finishing the upstairs to my home for several years.  In the 
ceilings I have Owens-Corning Fiberglas insulation with the kraft paper 
vapor barrier.  I just noticed tar on the paper in the spots where currently 
used wiring touches the paper.  It appears that the warming of the wire 
during normal use over the years has caused the tar on the Fiberglas 
side of the insulation to seep through.

Has anyone else ever noticed this phenomenon and is there any risk 
involved. such as, the tar reacting with the wiring insulation and 
eventually causing it to break down?  I should note that the current loading 
on the wire is well within limits.

Loren 

    Does anyone know where to get good prices on insulation
    (both faced and unfaced)?  Does Spags carry it?  How 'bout
    the 9 inch stuff.  Not every place seems to carry it.
    
    TM
    

    While we're at it, has anyone heard of 19"-wide insulation?  If
    so, where can I pick up some at a reasonable price?  The joists
    under the main part of my house are 19" on center.
    
    Jim

    re: .5
    I think you are out of luck.  However, what you can do is get
    insulation for 24" o.c. and, while it is still rolled up, cut 
    a slice off one end with a handsaw.  I used this stunt when
    I insulated my garage, with sort-of 12" o.c. joists.  In my
    case I could saw it down the middle and use both halves, but
    you ought to be able to cut off about 4" just as well. You'll
    want to cut it slightly wide so it's a snug fit, of course.
    

    RE: .5
    
    NO!  You are not out of luck!  I bought 19" insulation at Somerville
    Lumber last year.  They had it on special.  They may have to order
    it but it does exist for us owners of 20" oc construction.  Sure
    in hell beats cutting that crap lengthwise!  Which reminds me, I
    still have half of it to put in :-{
    
    Phil

    
    Is there anyone that has an insulation blower that I can rent
    for a day?  I need it to do a small section and Taylor Rental
    will not rent it by the hour and charges $70/day ( which is
    more than what I want to pay). 
    
    - Ted

    Insulation is sold usually in 15" rolls.  However, I need to insulate
    in two places.  One measures, in the space from stud to stud, 16",
    while the other place measures 16.5".
    
    Will the standard roll fit?

    I think I've seen that Grossmans will lend these out if you buy
    some insulation from them.  Maybe if you buy one or two obligatory
    bags they'll let you take it.  Then again, if you asked real nice
    they may just let you use it anyway.  For $70 bucks, its worth a
    shot...
    
    Phil

    
    	The standard roll of kraft faced insulation would probably just
    	about make it in the 16" slot as the the facing folds out to
    	allow the insulation to be secured to the studs... not too sure
    	about the 16.5" space however... you also have to consider that
    	if you try to put the insulation in a space that is wider than
    	recommended, you may get cold spots.
    
    /Kevin

    re: .1
    
      I believe their minimum purchase is 10 bags to get 'FREE' use
    of the machine.  
    
    -Jim
    

        The standard 15" roll should fit nicely after you've tacked on a
    length of strapping to each stud.

    >            The standard 15" roll should fit nicely after you've tacked on a
    >    length of strapping to each stud.

        Sorry, but what is strapping?
    

     Strapping is about the cheapest wood you can get.  I think it's 1x3
     (which actually is 3/4" x 2 1/2").  Pine probably.  I think, if you
     go to Grossman's, or anywhere, and ask for strapping, they'll know.

Pls be aware that insulation is also sold in 24 inch widths as well.
     this can of course be cut down to any width less than this   .
    

Or you could just pop another stud into each of the sections you're 
insulating.  

    
    I'm contemplating blowing insulation into walls of a bedroom I'm
    renovating, blowing the stuff in from the inside walls.
    
    How big of a hole do you usually have to drill to get the blower nozzle
    in?   
    
    Is this a really messy job?
                                                        
    How cost-effective is blowing in insulation, how many years does
    it take to recoup you original investment?  I'm talking about side
    walls, not attic insulation.  Attic I believe is the most important
    area to insulate, and mine is already done.
    
    Right, Grossmans will let you borrow their blower (you have to leave
    a 50 buck deposit) and have to buy 10 bags (60 bucks worth).  Thats
    the route I'm going to take when I get around to it.
                                               
    Steve
    

    Re: .2:   Buy 10 bags (heck, make it 12 so they don't guess) and get
    the blower.   Bring the blower back on Monday.   Return the unused
    insulation (unopened) on Friday.   No, I really didn't say that.
    Slap. 

         
    RE: .4
    
    Yea, I thought about that.  I think I'll ask the salesperson and
    see what's best (there usually candid about this too - I don't
    think they work on commision).
    
    RE: .3
    
    I don't know how big the opening has to be.  I'm putting mine
    between the bathroom walls that I share with a neihbor ( this
    is a townhouse complex) so I can pull the medicine cabinet out
    to blow the stuff in.  I'll only need 3 or 4 bags, so that's why
    I really don't need it for the whole day.
    
    - Ted
    

I had a converted summer cottage that had stud/rafter placement on 17.5
and 25.5 inch centering respectfully.  I insulated using 24" wide, kraft
faced, and went perpendicular to the studs/rafters.  I finally discovered
that the craftsperson who built the place really used a framing square
-- it fit between the studs/rafters/joists perfectly!

This may be a reasonable place to bring this up...

What is the general feeling about faced vs unfaced insulation/plastic?  I once
talked to someone at Owens Corning who suggested that unfaced is almost ALWAYS
better if you use poluythylene as a vapor barrior since it's obviously tighter
than what comes on the faced insulation.  I guess the only argument for the
faced stuff might be that it may hold the insulation in place a little better.
Certainly not a problem with ceilings, AND the unfaced is cheaper!

-mark

    re: .0,.5
    
    Sounds like it won't work. When you pull the medicine cabinet you're
    only going to see one or two stud cavities.  The entire wall isn't
    hollow remember.  Plus, you'll only be able to insulate below the
    cabinet or it'll all fall back down in your face.  Can you get to
    the top of that wall from an attic?

    
    re: .6 
    
    Yes, I can get into the attic, but there is a 2x4 that joins the two
    walls together and I'm affraid to take it off.  Don't you think
    that I might do some dammage if I do this?  
    
    Also, I think I can get access all of the inside wall from the
    medicine cabinet. 

    Why are you insulating an interior wall in the first place? If it's
    for sound deadening, I don't think you'll be that successful, and
    again I can't see how you'll get insulation to the top of the wall
    with a hole the size of a medicine cabinet, good luck anyways....
    
    
    							john
    

    Hope someone reads this.  If not, I'll refile it as a new note.
    I'm planning to add more insulation in my attic (crawlspace).  Turns
    out that they never put in a vapor barrier.  The house is very dry.
    THe attic has reasonable ventilation (2 vents on opposite sides).
    The insulation is blown in fiberglass.  I'll be adding blown cellulose.
    My bathroom fans do not vent to the outside, but I plan to add enough
    vent hose to reach the attic vents as part of this project.  The
    kitchen dose not even vent into the attic.
    
    Thats the facts.  The question is:  I plan to add a vapor barrier
    below all of the insulation, probably just 4-mil plastic.  Do I
    install the barrier just between the joists, or do I go right over
    the joists to really seal up the attic?  Otherwise, the space below
    each joist is a place for moisture to escape.  For example:
                                              
                   Here?
     ___            ___            
     | | Here, yes. | |   
    _| |____________| |___________etc...                       
    
    Thanks much,
    Andy

So, you're going to sweep up the existing blown fiberglass insulation, 
put the vapor barrier under it, and then put back the blown 
fiberglass, and add blown celluose (6"? 8"?) on top.

sounds like fun.....

Suggestion:

In the condo I used to live in, I had about 4" of blown fluff (I think
it was fiberglass) with an R of about 2.2/inch.  I added 6" of blown
celluose (r=3.7/inch) bringing my total R up to about 30.  I chose blown
celluose because it is impervious to moisture, and I also did not have
a vapor barrier. This worked quite well.  I would recommend the same,
OR, put in 8" of blown celluose (shouldn't cost much more), and act as
if the fluff isn't there.  Then, you won't need the vapor barrier and
all the P*A*I*N involved in sweeping UP insulation. 

I'm not sure I completely follow you.  There's virtually no way to get the 
plastic in between the joists and the sheetrock.  The best you could do is to
remove the insulation (like .-1 said), then cut strips of plastic to place at 
the bottem of each channel of joists.  BUT - if this isn't water tight, there's
really not a point in doing it, so I guess you'd then have to run the plastic up
an inch or so on each side the the joist and then nail some kind of strapping to
it to form a tight seal.

Is this what you had intended?  

-mark

    
    RE: .10
    
    >>I chose blown celluose because it is impervious to moisture ...
    
    Could you explain?  I've never heard this before.
    
    Thanks,
     tm
    

    I'm not sure if I completely follow me!!  8^)  Since I'm gonna spend
    the time up there, I want to do the right thing once.  So, my intention
    was to add a vapor barrier with plastic.  Let's assume that the
    attic is 35' x 20'.  Let's assume that I got a continueous sheet of
    plastic that was 35' x (20' + # of joists).  Since each joist is
    a 2x6, figure that the up, over, and down length is 1 foot.  So,
    in this way, I could have one sheet of plastic and seal the attic
    including the joists, but not under the joists, as I tried to diagram
    in .9.  I would staple the plastic into the joists.
    
    If this is dumb, please feel free to say so!
    
    RE .10, I really don't mind moving the old insulation around up
    there.  It moves easily.  I'm keeping it because I'm on a tight
    budget.  I may consider moving all of the fiberglass to key positions,
    out of the way.  Notwithstanding where or what insulation is up
    there (and I *do* appreciate the advice), the key question is the
    barrier, to keep moisture in the living space, I think.
    
    Thanks for all the help,
    Andy
    

    The ideal is to have the vapor barrier beneath the 2x6 which means
    replacing the ceilings.
    
    Since the R value of a 2x6 is probably on the order of .2 to .5
    what you are doing is acceptable.  You don't seem to mind moving
    the existing insulation.
    
    What would NOT be acceptable is to put strips of plastic in the
    troughs even stapled to the joists.
    
    Be careful in the eaves that you don't block airflow from the soffit
    or edge vents.

    Andy,
    	Why staple???  If I was going to put in a vapor barrier I would
    start at one end of the attic with my plastic in a big roll.  I
    would take the insulation out of the first two "bays"...space between
    the rafters.
    	Starting at the wall I would tape the plastic...spread it into
    the first bay and over the rafter....leaving the roll in the second
    bay.  I would then move the insulation from bay three to bay one...move
    the roll from bay two to bay three....and so on.  At a break in
    the plastic I would tape the two pieces together.
    	One problem with this is what to do with the insulation in the
    first two bays...darn....I knew that I was forgetting something.
    	But anyway...I wouldn't staple at all...just let the insulation
    hold the plastic in place.
    Ric

    I believe there are some types of paint that act like a vapor barrier.
    Why not skip the plastic all together and paint a vapor barier on the
    ceilings below and add insulation above? 
    
    Charly

At the cost of a few $:

1) The vapor barrier does not have to be all the way at the inside of the 
insulation, 2/3 will do.  In other words, if there are 6" of insulation now, 
you could just tack down the vapor barrier on TOP of the rafters, without 
disturbing any of the existing insulation, and then put 12" of new insulation 
on top.  9" on top would actually probably be enough so that the vapor barrier 
worked effectively.

2) Vapor barrier paint.  There really is such a thing, although I don't know 
where it can be purchased.  It's probably expensive, though.

Personally, I'd go with option #1.  You get the added benefit of the extra 
insulation.  But then again I think I'd do anything rather than shuffle around
an entire attic worth of old, dusty, loose insulation. 

Paul

I've been lead to believe that blown celluose does not lose its R 
value if exposed to moisture

    re .15, you know, that's not a bad idea.  For the most part, a blower
    might not even be necessary then.   Hmmmm....
    
    RE .17, my concern with putting the vapor barrier above the existing
    insulation is from other information, in this notes file and elswhere,
    which indicates that the insulation below the barrier can absorb
    all th moisture escaping the living space, which will cause it to
    become useless.
    
    With regard to running plastic over the joists, is there any concern
    for the wood absorbing moisture and rotting?  How about draping
    it over the joists, then stapling (or using the weight of the
    insulation), then cutting the plastic atop the joists to allow them
    to "breathe"?
    
    Thanks very much for all of the replies!  This is great...
    Andy

why not ask the experts?  I called Owens-Corning just a few weeks ago and talked
to Jim Porter (though I suspect there are lots of people who can help).  Just
tell them you'd like to ask someone a few questions about a home insulation
problem.  You know there techies types, locked in all day and never allowed to
talk to real people.  They LOVE to talk to customers.

the number is 419-248-8000

let us know what they have to say...

-mark

    RE: .20
    
    I did call Jim Porter.  He was very helpful.  He recommended NOT
    putting the barrier above the insulation; clearly advisable to put
    it below.  He said that a rule of thumb to indicate whether a barrier
    is or is not necessary is that there should be 1 sq ft of ventilation
    (vents) for every 150 sq foot of attic.  I don't qualify (2 sq ft
    of vent, 700+ sq feet of attic).  He said that if I could move the
    insulation and install a barrier (either faced bats or plastic),
    it couldn't hurt.  But, if we haven't had any moisture problems,
    we can probably just add more insulation w/o a barrier.  He still
    recommended the barrier, though.
    
    Other useful information.  Barriers are rated by PERMs, i.e.
    permiability, with a kraft face being 1 perm, foil face being .5 perm,
    plastic less that .1 perm.  THe lower the number, the better the
    barrier.  He said that if you call a paint manufacturer, they should be
    able to tell you how many perms a given brand/type of paint has.  He
    said that there definitely ARE barrier paints.
    
    Great idea to call the guy.   Thanks.
    Andy

I have two applications for VERY HIGH R-value material: 

1) getting R-30 in a 4" space between bedroom ceiling and attic floor.
2) Wrapping 28" x 6" heating duct hung 1.5" from joist.

Since these are real DIY jobs, I'd also like to avoid fiberglass for the
obvious reasons.  This file has cryptic references to non-fiberglass
materials, noting that they are 'more expensive'.  Does anyone have more
details on these materials?  For example (from .1 of this note)

>    beadboard			4/inch
>    styrofoam board		5/inch
>    isocyanate			6 or 7/inch  [what is this stuff?????]

There is also a material available called Reflectix, which claims an R-value of
14/inch provided you put a 1/2" air space below it.  State Lumber sells it for
$.50/sq. ft. 

What I'd like, ideally, is an easy-to-work-with, high-R/inch material. The
applications require little enough that I can handle high cost.  Suggestions?
thanx/j

I have a problem very similar to .0, except (sigh) more difficult.

Over my garage is the master bedroom and 1/2 of a den.  These areas are cold. 
Furthermore, they don't get much heat, because the heating ducts travel 
through the (poorly insulated) garage ceiling, which is finished (joists not 
exposed).  Also,

o In the attic over these rooms is 6" of rolled fiberglass over 1" of
  'packaged' celluose  (total R, ~ 20). 

o The wall just over the floor of the master bedroom is significantly colder
  than high up on the wall. 

I have fixed the formerly large cracks around the garage door, but, as
mentioned earlier, I don't want to make the garage TOO warm.  Has anyone
solved this problem?  The only thing I have thought of was to attach some kind
of sheet insulation (maybe reflective-type) to the garage ceiling. 

thanx/j

I've been thinking about high R-value material also.  I've recently seen this
"stuff" in the lumber stores and can't remember what it's called.  Essentially,
it's 1/2" bubble wrap coated on both sides with some kind of foil.  The claim
was something around R-14 but I could be off by a few.  My intention was to
insulate my ceiling with regular unfaced insulation and add this stuff for a
vapor barrier.  My plan is to first call both manufacturers and get their 
opinion of what I want to do.

-mark

>I've recently seen this "stuff" in the lumber stores and can't
>remember what it's called.  Essentially, it's 1/2" bubble wrap coated
>on both sides with some kind of foil.  The claim was something around
>R-14 but I could be off by a few.  My intention was to insulate my
>ceiling with regular unfaced insulation and add this stuff for a vapor
>barrier.  My plan is to first call both manufacturers and get their
>opinion of what I want to do. 

The stuff is called Reflectex and sells for about $.50/sqft most places 
($.45/sqft in 100 foot rolls).  It indeed does seem to provide R-14, 
PROVIDED that you have 1/2" air space on both sides - if it is 
touching the surface it is meant to insulate, all bets are off.  It 
seems to be recommended primarly for wall insulation, though you can 
use it for floor/ceiling insulation if you staple it about 1/2 way 
between the top and bottom of the joists.  It should not be used next 
to existing fiberglas insulation, as it will 'seal in' moisture in the 
fiberglas.  How did I get this info?  The lumber store gave the 
company 800 number, and they were quite helpful.

One other thing - although the salesman said it was ok, the guy at the 
company was concerned about my using it as duct insulation, as its not 
supposed to see temperatures above 180degF.  It does have an A-1 fire 
code rating, though.

> It should not be used next 
> to existing fiberglas insulation, as it will 'seal in' moisture in the 
> fiberglas.  

Thanks for the info, but I have one question.  Why is this any difference than
a vapor barrier which by design seals OUT moisture from the fiberglas?

-mark

>> It should not be used next 
>> to existing fiberglas insulation, as it will 'seal in' moisture in the 
>> fiberglas.  
>
>Thanks for the info, but I have one question.  Why is this any difference than
>a vapor barrier which by design seals OUT moisture from the fiberglas?

actually I asked this question in reference to sealing my garage 
ceiling from the underside - he told me not to seal in the fiberglas, 

I think the point is that it does seal, and you have to treat it as if 
it was a vapor barrier both wways

    re .15, .16:
    
    Yes, that makes sense. It sounds OK to use it against the fiberglas
    on the _warm_ side (although you lose some insulating value because
    there's no radiation gap), but if you put it on the _cold_ side
    (like on the ceiling of a garage), you stand to trap any moisture
    that may leak through the warm-side vapor barrier.

How to insulated the ceiling of a finished garage (I think): 

A recommended contractor offered to drill a series of 2" holes in my garage
ceiling, and blow celluose into the space between the joists, then plaster the
holes (recreating the 'swirled' effect as best he can). Cost: ~$1/sq. ft. 
(total job, about $350).  As I sad in the last note, the garage is over my
bedrooms, which have chilly floors, with some real cold spots, and cold around
the bottom 1' of wall.  He says he can also insulate the sill area.  Anyone
have experience with this - know if it will help, (I have about R15 in the 
attic) and can help me explain how insulating a floor helps when heat rises?
thanx 

From:	12284::CURTIS       "Dick 'Aristotle' Curtis" 25-JAN-1988 10:42
To:	BINKLY::WINSTON
Subj:	insulating a floor

    Jeff,
    
    "... when heat rises..." is a popular mis-quote.  *Hot air* rises,
    and cold air sinks.  But just because it's cold doesn't mean that
    it can't get colder, if there is something colder (like an unheated
    garage) nearby as a convenient heat sink.
    
    If you're undecided about insulating the floor, try this:  take
    (preferably simultaneous) temperature measurements, at various heights
    along a wall (or in the interior, if you can come up with a way
    of stacking or suspending the thermometers).  It's quite likely
    that you'll find a stratification of temperature:  the hot air will
    rise to the ceiling, give up heat and sink;  but the air at the
    floor will never gain enough heat to rise, so you'll have a dependable
    pool of cold air to nip your ankles.
    
I've no experience with insulating, outside of buying the itchy pink stuff
and doing it myself, so I can't say what the good and bad prices are.  At
$1.00/sq.ft., doing a two-car garage would be on the order of $400;  I
guess that you'd have to consider what you get for the money.  I'm not sure
that it would cost much less if you tore out the ceiling, stapled
fiberglass in, and then put up new sheet-rock (WAG would be $250 to $300,
but that's without looking at prices -- it could easily be twice that, or
half that). 

For $400, I'd consider whether DIY would result in a substantial savings of
money (to pay for your time and effort), or a significantly better performance
or better looks when finished.

Regards,
Dick

	This spring I'll be finishing my sunroom project and up until
now was just going to insulate between the rafters of the cathedral
ceiling. But the past couple of snow storms have me conserned. The
snow on the roof area above the cathedral ceiling of my family room 
is alway fast in melting and its finished in this way. So now I think
I'll add 1 inch of rigid insulation but have a couple of questions.
	
	SEE DIAGRAM BELOW:

	Should the vapor barrier go on the inside or outside of the rigid
insulation? Do I even need one if I seal all the seems on the foil faced
rigid insulation with duct tape?

	Do I have to run strapping over the rigid insulation to secure
the blueboard to? I won't be doing my own blueboard and plaster job,
so I need to know what's the norm. If at all possible I preffer not to
use the strapping as I'll lose another inch of headroom.

	Where do the electral boxes get fastened? Right now they're fasten
to the roof rafters with 5/8 extention for finished ceiling. 


	Thanks all....

...Dave

  
			    		2X10 roof rafters

	Roofing 	 _____________________|______________________
Strofoam spacers ------> ----\_________/----| | |----\__________/----
                         *******************| v |********************
Fiberglass insulation	 *******************|   |********************
			 *******************|   |********************
Vapor Barrier ---------> --------------------------------------------
Rigid insulation ------> ############################################
1x3 Strapping ---------> WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
Blueboard & plaster ---> SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

wait a minute...

if you want to put rigid foam in, why bother with faced insulation?  the foam
would probably make an adequate one.  even if you don't put in rigid foam, I'd
still go with unfaced insulation and put in polyethylene.  The poly will do a 
MUCH better job than the facing on the insulation.  the money you save buying 
unfaced will then help offset the cost of the poly.

there is some new spaceage stuff that looks like bubble wrap and has foil on
both sides.  it's about 1/2" thick.  what I want to do, and I plan on calling
the manufacturers of that as well as owens-corning for their opinons:


		======================================
			||  air space	||
			||--------------||
			||		||
			||    unfaced	||
			||  insulation	||
			||--------------||
		  **********************************   bubble wrap stuff
		    ------------------------------
		    ------------------------------  strapping
								

the strapping is used for screwing the blueboard to.  it will obviously 
compress the bubble wrap over the rafters, but so what!  since the bubble wrap
is air-tight, IT will be my vapor barrior.

I foget what the R-Value of the bubble wrap is, but I think it's something like
R-14 or so.  That plus the fiberglas can easily put you over R-30!

-mark

The bubble stuff is called reflectix.  Call 800 ADD FOIL.
They will send you detailed info and a sample.  ITs R=14
provided it has air space on either side

    	Any ideas on the electrical boy question?
    
    	Or the to strap or not to starp question?
    
    ...Dave
    

I had a similar job done on a cathedral ceiling, and the carpenters didn't
use any strapping over the rigid insulation.  They double-checked to ensure
that the rafters were indeed 16" on center, and installed nailers wherever
this wasn't true, so the wallboard installers wouldn't have do too much
searching.  (The roof has some weird corners and angles that required some
advanced framing techniques). 


Re electrical boxes:  depends somewhat on what they're for.  If they're for
hanging lamps with big escutcheons, for example, the escutcheons will hide
a lot of problems with box mounting depth.  Other types of fixtures
(including switches and outlets) will be less forgiving, so you'll have to
be more precise in your box depth. 

In any case, the front of the box is supposed to be flush with the finished 
wall, or protruding slightly past the finished wall, into the room.  That's 
because:
    1. The box sides protect the (possibly flammable) wall materials from 
       the live wires inside the box
    2. The fixture that you mount on the front of the box is supposed to 
       make good metal-to-metal contact with the lip of the box, providing  
       ground continuity.  (Only applies to metal boxes and metal fixtures, 
       I guess).

So decide how you'll cover those rafters, calculate how thick it'll be, and
re-mount the boxes appropriately.  If the wall treatment is extremely thick
or if the boxes are shallow, there may not be enough of the box left in
contact with the rafter for sturdy mounting.  One workaround is to toenail 
a short board from one rafter to the next, and then nail the back of the
box onto that board.  Unfortunately, the placement of the short board
determines the box depth, and accurate placement while toenailing isn't
always easy. 

I couldn't find the vapor barrior note (it wasn't in the key word directory)
so I'll put in my latest comments here.  I finally called Owens Corning and
much to my surprise my thoughts on vapor barriors leave me all wet!

It turns out that if you ave adequate ventilation ("adequate" being the key
word), you should NOT put a vapor barrior in your ceiling as the air flow
will take all the moisture out of the house.  If you DO put in a vapor
barrior your windows may tend to sweat (Gee - didn't I see that comment in
a reply).  However, in the case of cathedral where air flow isn't as great as
in a standard ceiling, Owens Corning recommends a vapor barrior.  This may
cause sweating of the windows, but is felt to be necessay to account for reduced
air flow.

One final note - in the state of New York, vapor barriors are required by code.

-mark

    
    Hi Folks,
    
    I would like to revive this discussion.
    I have a ~90 year old house which costs *megabucks* to heat.
    I am considering blowing insulation into the walls.  Some of you
    have had insulation blown into the walls a while ago, and I would
    like to know how it has worked out.
    
    To those who have done this, or live in a house with blown-in
    insulation in the walls, I would be interested in knowing:
    
    1. What type (and age) house do you own?
    
    2. What type of insulation did you use?
    
    3. What effect did it have on your heating bills?
    
    4. Have you checked for evidence of rot and/or moisture in the
       walls, and if so, did you find any?
    

    
    Does anyone know where I can get rockwool insulation?
    I have tried to do some research on insulation, and
    it seems that rockwool is similar to fiberglass
    (which used to be called "glass-wool", I think), but
    it has a slightly better R-Value, and has less of a 
    tendency to absorb moisture than fiberglass.  My father
    put rockwool in his attic ~15 years ago.
    
    I don't really understand why it is so hard to find.
    I suspect that it has just gone "out of style", now
    that fiberglass is so well-known.

    1. What type (and age) house do you own?
	duplex garrison, built circa 1959
    
    2. What type of insulation did you use?
	cellulose (ground newspaper with fire retardent)
    
    3. What effect did it have on your heating bills?
	guestimate: 40% decrease in oil bill after walls done *and*
		6" fiberglass added in attic
    
    4. Have you checked for evidence of rot and/or moisture in the
       walls, and if so, did you find any?
	Did not check specifically at time of insulation, however did
	have some in a shower area where water leaked thru tiles.    

    In one way, this reply don't belong here, but in the context of
    its meaning, TAKE HEED (especially if you think Consumers Reports
    may be correct .. see also 8.2).
    
    I've been putting off insulating my old house (150+) because of
    the possibility of getting "wet" insulation.
    
    Recently my doctor suggested I add a HUMIDIFIER to my living space
    to help alleviate a nasal problem.
    
    Reading through the CR recomendations (in two or three references)
    they flatly stated DO NOT install a humidifier in a house without
     a vapor barrier because the humidity would pass right through the
    walls to the out of doors, and any insulation would become damp
    from the extra moisture !!
    
	So, INDIRECTLY you have another source that recommends NOT
    insulating house UNLESS it has a vapor barrier installed.
    
    
    Bob 

yes, but some types of insulation (certain celluouses, etc) are 
impervious to moisture and can be used where no vapor barrier exists
(also styrofoam, i think)

    A few 2 cent comments about blown in insulation;
    
    Ceilings, recently had my attic done. Called 10 contractors for
    quotes, 9 of them blow cellulose. I wanted fiberglass and found
    a guy in Chelmsford Ma, Bullock & Cocaran(something like that).
    Celluse is paper which tends to hold moisture, has to be treated
    at extra cost to deter rodents from eating it, and has been a suspect
    of more than a few house fires. Inch for inch cellulose has a better
    R value when its new but it settles unless you fluff it so after
    2-3 years you have less effectiveness than fiberglass. Fiberglass
    doesn't cost anymore per say, wont settle, rodents don't eat it,
    doesn't hold moisture and tends not to burn. You need more ventilation
    for cellulose in addition to baffles to keep the cellulose from
    blowing around and blocking the sophet vents.
    
    Walls, haven't done the walls yet, and may not. Some contractors
    require that you have no insulation at all before they will blow
    in. If you have 1-3" in batt type then they can't effectively blow
    in because the batt settles. 
    
    BTW, more contractors blow cellulose than fiberglass because it
    costs less, paper is cheaper than f/g and heavier equipment is required
    to blow f/g.                                

    Re: .20
    Mice may not eat fiberglass, but they just LOVE to make nests in
    it.  I found several fiberglass-lined mouse nests when I redid
    my roof last year.

    re: .20
    
    	You don't want blown fiberglass in your walls. Fiberglass is
    blown in in small balls. These balls have a marked tendency to catch
    on the nails which hold your siding on. This can cause blockages
    which leave voids in the insulation.
    
    	As far as cellulose being a fire hazard, could you please post
    some evidence. I researched it pretty carefully and found that it
    is virtually fire proof (it's treated with something).
    
    Alan
    

    How does one "cut" fiberglass insulation?  I have what looks like
    two 6" layers stuffed in my attic, covering everything, including
    the soffit vents.  I have to cut about a foot off each end.  What
    do I use?
    
    Elaine

>    How does one "cut" fiberglass insulation?  

You can use a standard razor knife.  Or if you can find pizza shears 
(long bladed scissors) you can use those.  I've used both with good 
results, but prefer the scissors 'cause I'm clumbsy.  The important 
items are the goggles, gloves and dust mask.

					>>>==>PStJTT

    Thanks!  I started with gloves last night, but it didn't take long 
    (about 30 secs) to scramble downstairs for the dust mask.  I'll
    just need goggles, and BIG scissors!
    
    8<)    <- me with goggles and mask, smile under mask
    
    Elaine

    re: .9
    
    	The quick, easy way to cut insulation requires two boards and
    a razor knife. You lay the insulation on one board where you want
    to cut, press it down with the other board and cut. If you're working
    on a subfloor or similar surface you can dispense with the bottom
    board.
    
    Alan

    I use big scissors for this job.  Just be sure to wear clothing
    that covers you completely, gloves, a hat, a mask, and goggles (I'll
    admit to really hating to wear goggles....).  When you get through,
    go directly to the washing machine and drop all your clothing inside,
    and then go directly to the shower!  Have someone follow you with
    a vacuum cleaner while you make this trek - cutting up batts of
    insulation will get little pieces of fiberglass ALL OVER you, and
    all over everywhere else as well.

    re: .12
    
    There's an idea!  There is a bit of subfloor I could use for the
    bottom board, and there's a couple of loose boards up there I could
    use for the top!
    
    re: .13
    
    The insulation is already in the attic.  I just have to make it
    smaller.  The mess will mostly stay up there.  I just have to figure
    out what to do with the 900 cubic feet of extra insulation I'm going
    to remove!
    
    This discussion is making me itch again.  I wonder how many others
    are feeling the same way!
    
    Elaine

    You scratch my back, I'll scratch yours!?!
    

    There's always use for some extra insulation. You could stuff it
    where the floor meets the top of the foundation walls (sill?). I
    just had an energy audit done on our house. That is one of the things
    that has to get done. The guy that did the audit told me it is amazing
    how many old as well as new houses have very little insulation there.
    This keeps the cellar cold which then keeps your floor cold.

The last insullation job I did I got one of those environmental clean-up suits
one uses for chemical spills.  I could't believe it but I even itched after
wearing that!

Although a miserable time to insulate is when it's hot outside, that's the time
I prefer since when I'm done I run to the local pond and go swimming for a long
time.  I've never met the shower yet than can remove the itch (nor a pond either
for that matter, but it helps...).

-mark

    Some one once told me to take a COLD shower after insulating. A hot
    shower will open the pores in your skin and the fiberglass fibers can
    get stuck in there and bother you for a while. The cold shower keeps
    the pores closed so that you can wash the fibergalss off and down the
    drain, then you can take a warm shower to warm up. 
    
    I tried it last time I insulated and I wasn't bothered with itching
    afterwards as much as I have been in the past, BUT, it was difficult
    to jump into a cold shower and lather up. I kept saying to my self,
    "Brrrrrr this had better work...Brrrrr"
    
    CCCCCCCCCharly

    We had rock wool blown into the walls of our 95 year-old Victorian
    seven years ago.  The first year there was 25% saving on our heating
    bill and that winter was more severe than the previous one.  We
    figured it was about a 3-year payback.  No problems with moisture,
    mice, etc.  In summary, it was worth the expense.

    
    Re: .24
    
    Thanks for the info.  Your house seems pretty similar to mine.
    I have pretty much decided to blow in Rock Wool into my house,
    too.  I was concerned about the vapor barrier business, but
    then I learned about vapor barrier paints.  A book I have 
    recommends painting the outside walls with an oil-based enamel,
    followed by an alkyd paint.  
    
    Now could you tell me who did it, how much it cost, 
    when you had it done and the approximate size of your house
    (so I can compare).  You might want to put the info in the
    energy contractor note instead of this one, though.
    
    -therese
    

    The job was done by American Insulators of Voorhees, NJ.  I think
    they are an independent company.  We had the side walls and attic
    floor done in 1981 for about $2700.00.  The house is 27 feet wide
    x 25 feet deep with 10 ft. ceiling on the first floor and 8 ft.
    ceiling on the second.
 
                   

    
    
    Searching thru many notes, I didn't find this topic. Maybe I missed it.
    I am going to raise the roof on my slab ranch next summer. I have done
    all the initial planing and am going to go to the drawing board on most
    all items. I do however have one problem with many solutions but wanted
    to see if any noters have come across similar. The insulation in the
    attic is blown in and I want to take it completly out. Depending on the
    method, I will put it back upstairs on the new second floor attic or
    dump it off. It is 3" of blown in fiberglas and 10-15" of newspaper
    blown in if anyone is familiar with this stuss.I blew it in 7 years
    ago. The total depth on some spots reaches 15 at most. There is about
    1200 square feet of the stuff and the attic is trusses at 24" o.c.
    
    If I were to suck it out, can it be put in bags and reused? Sweep it
    over the side when I open the roof? These are the hints/suggestons I am
    looking for. Does anyone know of rental equipment for this sort of
    operation?
    
    
    chuck

re. < Note 2552.0 by MPGS::PARTAIN "Chuck Partain, KA1MWP" >
                        -< blown in insulaton removal >-


  Is your house anywhere near Upton, MA?  I need some blown in insulation
in my house...if we can find a hose long enough........:-}





On the serious side:  If you're going to add a second floor, insulation between 
floors wouldn't be all that bad.  It would keep an air conditioned room on
either side of the insulation a little cooler, if the other room wasn't AC'ed.
Also would provide sound insulation.  You might want to consider leaving
the insulation where it is.


Steve

    You're kidding about sweeping the insulation over side aren't you?
    I've been raising my roof for the last 2 months. One of the most
    unpleasant jobs was removing blown in insulation. I don't think
    there's an easy way. I covered up myself with coveralls, gloves, hat,  
    mask, and goggles and just removed the horrible stuff 1 handful
    at a time. I tried to suck the stuff out with a vacuum 
    (rented big industrial) but the thing filled up before I could even
    put a dent in the bays (area between rafters). If there was a way
    to compress the junk the vacuum would probably work better. After
    I removed most of the stuff, the big vacuum did a great job finishing 
    up. 
    I did keep the stuff in plastic bags, thinking that I may use the stuff
    over but I NEVER WANT TO TOUCH THAT $%^& AGAIN! 
    I've been putting a few bags out for the trash every week.
    If you can't get at an area, the blown is a good compromise but I
    don't like using the stuff.
    Norm Morin
    

	Removing blown in insulation does not sound like fun, removing blown in 
	fiberglass is insane.  MAN DIES; ITCHES TO DEATH   Do you also realize 
	that you have about 280 bags of fluff(1200 cu. ft*7 gal per cu ft/30 
	gal per bag).  I think insulation is classified as special waste.  If
	you have small quanities you can dispose of it normally, but large 
	industrial quanities require dump permits which could cost more then 
	new insulation.

	If you insist on removing the insulation, cover everything around 
	the house.  Tack 20x20 sheets of 6-10mil plastic to the side of the old 
	roof and tack the other ends to step ladders or staging about 10 ft 
	from the house.  Fill and fold up. This will require a pickup and 25-30 
	trips to the dump.  Or only remove the insulation which is above the 
	rafters, set aside and apply to the new ceiling.

	The best tool for moving around blown in insulation is a wicker leaf 
	rake.  If you are doing this in an attic use a small wicker "kids" rake.

	Side note:  To increase the capacity of a shop vac use a large plastic 
	garbage can(30+gal) between the vacuum and nozzle.  This will also 
	automatically bag your sweepings.  

	Brian

    Almost every house I've seen during its construction has been wrapped with
Tyvek.  In preparing to have our house built, I've gotten conflicting advice -
from lumber supply places and a framer.  Their opinions:

    - get Typar.  "I've seen clapboard pulled off fairly new houses and the
      Tyvek had disintegrated."
    - get <mumble(I_forget)brand_name>.  "Typar stinks.  And this stuff is
      as good as Tyvek, which is the best."
    - (from the framer) "I'll put up what you tell me, but I won't use any
      on my own new house.  Nice, tight plywood sheathing, plus the plastic
      wrap on the inside of your insulation is plenty."

    Agreement?  Comments?

    I'd tend to agree with the framer.  Seems to me that the practice
    of wrapping the house with something is left over from the days
    when people used shiplap boards to sheath a house.  The only places
    you'll get drafts with plywood sheathing is through the (few)
    horizontal cracks that occur where there is no backup framing. If the
    thought of those few drafts bothers you, invest $5 in a roll of duct 
    tape and tape up the cracks.  I wouldn't worry about it.  I think
    Tyvek is a high-tech (expensive) solution of a non-existent problem.

    Not to beat a dead horse, but our house has rock wool blown in,
    including the attic.  I'm removing a couple of walls, etc., now,
    and I'm wondering....can I or should I reuse the rock wool for various
    small cracks, etc., provided I keep it free of dirt and sawdust,
    etc.?  Also, what is the R-factor on rock wool?  (For an average
    wall...old 2x4's, actually 2 full inches x 4 full inches, studs
    16" on center).
    

    In any case, your walls should all be insulated AND vapor barriered
    so even if your siding AND sheathing have a miniscule gap to allow
    a draft, where's it going to go?
    
    It is better to have some ventilation to the outside in case of
    a moisture problem.
    
    Alan

	I'd agree with steve and the framer that it's not clear what
	savings, if any, you receive with the tyvek, provided as was
	stated, that the plywood siding and the finish siding is good
	and tight, however, I'd disagree about the cost.  Considering
	that for a $100,000 house the cost of tyvek is approximately
	1/10 of 1 percent of the total budget, it is not a bad investment
	in lieu of hard data, for the piece of mind it gives you, even if
	only perceived, of having the extra protection.  The tyvek really
	does quite a good job of stopping wind and also repels water which
	helps keep moisture away from the plywood if you end up with any
	gaps wherethe weather can get underneath your finish siding.  And
	it does allow ventilation so that moisture trapped or coming from
	the inside can escape to the outside.

	I covered all my plywood seams, both vertical and horizontal,
	with roof cement, then put the tyvek over that.  I think we
	only used one gallon for the entire house, and it not only
	sealed the seams but helped hold the tyvek in place when it came
	time to staple it up.

	In my opinion, for the cost of the tyvek (about $100), even if
	the advantages are minimal, it is worth the risk of investment.
	And who knows, maybe if we end up in an energy crunch again some-
	time, the fact that you have the tyvek installed may be a selling
	point.

    I agree that the data on Tyvek/Typar/Ty??? and house wraping is
    confusing! 
    
    A couple of years ago, it was the lastest thing and everyone was
    pushing it. I was talking to a framer friend last week and he said that
    the "current thinking" is that plywood and your siding is all that's
    needed or even desired! There's even conflicting advice on using tar
    paper under roof shingles! 
    
    As far as selecting a brand, early this summer I heard that DuPont
    now recommends that it's Tyvek be covered immediately (like the SAME
    DAY) other wise, it may lose it's special properties, what ever
    they may be.
    
    The sales pamphlet for TyPar (made by ???) on the other hand lists one
    of the advantages of using TyPar as a house wrap to protect the
    house/plywood before the final siding is installed, even if its for
    several months! 
    
    The one thing that house wraps are good for is putting money in the
    manufacturers pockets. :-)

    Charly

    In the last two years, since I've been watching construction, I've noticed
    that Ty* is usually used in conjunction with particle board/press
    board/wafer board.  I only notice it when the board is left exposed
    to the elements before siding.  Perhaps it is just a precaution
    against moisture before the siding is put up.
    
    Also isn't it true that these particle board products don't have
    as much structural integrity as plywood when it delaminates?  In 
    this case you want to be very sure it doesn't encounter moisture...
    ever.
    
    Elaine

    
    As to whether or not an air infiltration barrier is important in
    modern construction, I don't know.  Both vapor barriers and to a
    lesser extent air infiltration barriers may contribute to radon
    problems.
    
    However, I do know that if I were to choose an infiltration barrier,
    it would probably be Typar.  Typar is made of woven polypropylene,
    and seems to be pretty strong.
    
    -tm
    
    

    
    The stuff I've read says rock wool has an R factor slightly better 
    than fiberglass.  Warning - the stuff is nasty to lungs like
    fiberglass, so wearing a mask and gloves would be a good idea.
    
    -tm
    

	I would do what your framer/finisher recommends.  A contractor who 
	does not recommend or normally uses tyvek will usually screw up the 
	job so bad that it will be useless.  If you are in the Townsend, MA 
	area I can show you a couple of bad tyvek jobs done by a contractor 
	that I would not trust to build a doghouse.  

	Recommendations from building supply places are only as good as 
	what they stock and what their margins are.  I highly recommend an 
	exterior wind/moisture barrier in addition to interior vapor barrier in 
	the wind wet northeast, especially after living in a plywood sheathed 
	house the I can here puffing up in the wind.
	
	Tyvek allows gases and liquids to pass at a controlled rate which is
	fast enough to allow water vapor to escape from within wall, but slow
	enough to allow exterior moisture to evaporate and winds not to blow 
	through.  Exposure to weather does not effect the performance of the 
	material.  This is based on exposure test I did using disk sleeves.  
	Exposure to weather can effect the installation.  Tyvek is light weight
	with a large sail area so the installation can be ripped out with 
	the slightest breeze.  Dupont recommends that the tyvek be removed and 
	reinstalled, but most contractors do not do this.  The problem is 
	compounded by the fact that the framing crew is not the same as the 
	siding crew and window installers, so the tyvek will be exposed for 
	upto 3 months.  

	Typar, according to a contractor I talked to, also allows vapor 
	out, but does not let moisture or wind in.  He uses it(he use to use 
	tyvek) because it is heavier thus easier to handle.  He also said it 
	was easier to double lap windows.  I will conduct my own test in the 
	next year.  

	The big disadvantage of tar paper is that it does not allow for the 
	escape of moisture.  Some people also say that the oils in the paper 
	cause water to evaporate slower.  

	Brian

    re: .8
    
    did you mean me?  I didn't want to imply that the ty* disintegrated.
    I guessed that it is used to keep the wood from disintegrating.
    
    Elaine
    

    Re: .8, No, he meant me, in the base note.  A lumber supply guy implied it
had lost its effectiveness by the time the clapboards came off n years after
they'd been installed (I don't know how many years).  He also said, contrary
to what .7 said, that the manufacturer says to install siding RIGHT AFTER
the Tyvek is put up - within a couple of days - because it IS affected
negatively by exposure to the sun.  The lumber guy thought that might be the
reason the Tyvek had "disintegrated" (my word, not his).

    Sounds to me like we have a lot of rumor and little first-hand
    knowledge going on here.  Maybe the lumber supply guy who had negative
    things to say was talking about a version of the product that has
    been improved, or maybe it's level of "disintigration" was, in fact,
    negligible.  (Or maybe nobody takes off their siding often enough
    to know waht really DOES happen under there!)
    
    It would be intersting to know if there are any "Consumer Reports-type"
    analyses of this stuff, that we could get ahold of. If they're positive
    Dupont would have them, no doubt.  But where to check if they are
    negative...
    
    Wind barriers can contribute to radon problems, but if you're in
    a risk area, you should look into PROPER ventilation systems to
    handle that, not rely on "leaks".  Also, electric companies have
    a lot to say on the subject of the energy conservation values to
    wind barriers.  Unless I read/hear some compelling evidence to the
    contrary in the meantime, I intend to use one when I build (about
    2 years, probably.)
    
    Sherry

    This Old House certainly believes in it.
    
    (or is that the kiss of death?)

<    Sounds to me like we have a lot of rumor and little first-hand
<    knowledge going on here.

	Dupont does publish a technical brochure for builders that I have 
	someplace at home.  Try writing them, but I am not sure they will 
	let laymen have it.  

	I would not believe anyone who said they have seen deterioration on 
	a job.  Tyvek has not been on the market long enough(5-6years?) for 
	people to be residing their houses.

	Contractor:  Gee, that tyvek is lousy stuff look at all the holes in it.

	Homeowner:  Those are the nail holes, you idiot.

Brian

One thing to note whether or not you use Tyvek is that you want some ventilation
through your siding (as I previous note stated I would NEVER consider sealing
the seams of my plywood) to allow the water vapor to get out.  In an earlier
note years ago I think I put in some stuff I was told by an engineer from
Owens-Corning about the porocity of walls.

Essentially there are 2 barriors on each side of the insulation.  The one on the
inside, the traditional vapor barrier, is intended to keep moisture for passing
through the sheetrock/plaster and onto the insulation.  However, most barriers
are not 100%.  Furthermore, there is a second barrior, namely the exterior
sheathing of the house.  In the old days, this exterior barrier was essentially
swiss cheese and anything that passed through the first barrior kept on going.
Today, everyone uses plywood or some other sort of material with lots of water-
proof glue.  The result is a fairly tight seal that can trap water vapor inside
the wall cavity.  I was told a horror story where someone made the exterior
barrior so tight that the inside structure (studs and plywood) rotted out.  I
suspect this is an extreme.

Anyhow, as a previous note said, the Tyvek at least allows the water vapor to
keep on going and still keeps the wind out, much like Gore-Tex does for 
clothing.

-mark

    Four years ago I built the first half of my house ajoining a trailer.
    
    At that time tyvek was the "in" thing for two reasons already stated.
    First as a wind barrier and second to allow moisture to pass in
    one direction only.
    
    Last spring I removed the trailer and added the second half of my
    house.  When it came time to put up the siding I had to take down
    a few pieces of the verticle shiplap to make the transition look
    like it wasn't done in two steps.
    
    The tyvek installed four years ago still looked and felt like new.
    If it does deteriorate, it doesn't in four years.
    
    When the tyvek was put up, it was in the middle of November.  The
    amount of wind barrier it provided made it feel 10 to 15 degrees
    warmer inside.
    
    My opinion is that the tyvek is well worth the investment.  In one
    of the previous replys it was said to cost $100, it was more like
    $250 for a roll 9' X 150'.
    
    To each his own opinion........
    Greg

    I don't understand how wind can pass through exterior siding,
    sheathing, 6 inches of insulation, vapor barrior and finally sheetrock
    that is taped at the joints.
    
    I went no tyvek because $ 300 is $300. Duck Tape at Sheathing joints,
    Caulk around  windows and doors and follow the insulators with extra
    insulation around windows, outlets, etc.  has provided me a tight
    house.
     

    The wind doesn't pass through sheetrock, but it can set up a howler
    of a gale through outlet and switch boxes and the spaces around
    windows.  If air can infiltrate from the outside, it sets up a
    pressure differential inside the wall which results in noticeable
    drafts.
    
    			Steve

>    The wind doesn't pass through sheetrock, but it can set up a howler of
>    a gale through outlet and switch boxes and the spaces around windows.
>    If air can infiltrate from the outside, it sets up a pressure
>    differential inside the wall which results in noticeable drafts. 

    
    Any combustion in the house (furnace, fireplace, etc.,) that vents to
    the outside reduces the amount of air in the house. That sets up a
    pressure differential with respect to the outside that causes every
    little pinhole to become a draft. The easiest way to eliminate drafts
    is to equalize the pressure. 

>   Any combustion in the house (furnace, fireplace, etc.,) that vents to
>   the outside reduces the amount of air in the house. That sets up a
>   pressure differential with respect to the outside that causes every
>   little pinhole to become a draft. The easiest way to eliminate drafts
>   is to equalize the pressure. 

    OK, I'll bite.  How does one equalize the pressure?  No combustion?  :-)
Or expensive air-to-air heat exchanger?  Or for-free drafts?

	> OK I'll bite.  How does one equalize the pressure?

	Air-Shredder ?!??!!??!




	Seriously.  One way to help reduce pressure differentiation is to
	have the furnace get it's combustion air supply from the outside.

>    Seriously.  One way to help reduce pressure differentiation is to have
>    the furnace get it's combustion air supply from the outside. 

    
    Houses used to have drafty basements, and the combustion air supply for
    the furnace was not a problem. In these energy crisis years, people try
    to make their basements airtight. 
    
    When I lived in the MidWest, an outside combustion air supply for the
    furnace was code for new houses, and 'strongly recommended' for used
    houses. I installed one, and all of my drafts disappeared. The house
    stopped filling up with exhaust fumes from the attached garage, also. 
                                                
    Done properly, they don't cool the basement.

      Approximately  3 years after our house was wraped in TYVEK and the
      sided we build a garage  which  attached  to  the  house  via  and
      enclosed breezway. I removed the siding and TYVEK from the portion
      of the orignal wal that was now inside the  breezway.   The  TYVEK
      appeared to me to be in perfect condition.
      
      So far as thinking you don't need TYVEK or some similar product --
      I can see only two reasons:  Either you don't think  you  need  to
      stop  air  infilitration  or  you think you can stop it some other
      way.  In the first case, why not just leave your windows open  all
      winter?  In the second case, well, in theory you should be able to
      get a tight  house  by  making  all  the  framine/sheathing/siding
      installation perfect.  I practice, forget it.  TYVEK is relatively
      inexpensive "insurance" that can make  up  for  a  lot  of  little
      imperfections. 
      
      So far as one wrap product vs.  another -- I like TYVEK or similar
      spun fiber products.  I don't like what was used on  our  garrage,
      which  was  a a plastic film with lots of tiny "pin holes".  But I
      suspect that they all work about as well.

    RE: a few back
    
    	DuPont says that Tyvek can be affected by untraviolet rays;
    	that is why they say to cover it 'soon'.  However, I don't know
    	what effect the ultraviolet rays have.  Anybody know?
    
    One thing I ran into when building my family room: having Tyvek
    on the exterior with all the windows and doors in was sufficient
    to allow the building inspector to do the framing inspection.  (The
    exterior had to be weather-proof, simple sheathing was not good
    enough.)
    
    - Mark

re .11:
    
    Wind barriers can contribute to radon problems, but if you're in
    a risk area, you should look into PROPER ventilation systems to
    handle that, not rely on "leaks".  

The September issue of Practical Homeowner claims that the latest opinion
on Radon is that it does not really leak into your basement, but rather is
sucked in by the pressure differential.  Pressure differential is caused
by fans blowing out, by furnace combustion, and by the wind blowing past
and creating a vacuum that sucks air through cracks in the walls.  

So a wind barrier may be a net positive on Radon, ie its effects at
keeping Radon from being sucked in may overwhelm its tendency to keep
Radon from leaking out.  In any case, controlled ventilation is better
than uncontrolled, whether for Radon, household pollutants, or temperature.

	Enjoy,
	Larry

    	Does anyone know of a place that I can buy insulation for my
    FHA ductwork?  The stuff I'm looking for is 1.5" thick with a foil
    facing.  I've seen it on the ductwork here at APO and it is
    manufactured by OWENS-CORNING.  Does anyone have a phone number
    for OWENS-CORNING?
    
    					=Ralph=
    

    
    	Have you checked sears?  I saw some at the Mall of NH a short
    while ago.  I can't remember the price, but it didn't seem to be
    too bad.

    
    I saw this stuff at MOORE Lumber in Littleton, Ma. Saturday.
    It was in rolls about 2' in diameter and about 36" wide. 
    No idea of cost since I wasn't interested at that time.

why not call some insulation contractors and ask them -
though, you can probably get it at a large plumbing supply house 
(that's where many of them go)

  	Running a combustion air vent to lower the pressure differential
    has some problems as well.  Your combustion heat sources (furnace,
    woodstove, fireplace, etc) both consume oxygen and the draft they
    produce vent alot of air up and out of the house.  If you introduce
    a dedicated air source you do indeed keep  alot of nice warm air
    in your living spaces.  But is this what you want?  This air is
    absorbing all the moisture from breathing, cooking, showering etc,
    absorbing all the fumes from the plethora of toxic chemicals under
    our sinks, in the bathroom, and on basement shelfs, as well as pollens,
    viruses, bacterias, radon, etc.  In other words, a tight structure is 
    not a good structure.  There has been much talk in the media lately
    about the "sick building" syndrome.  Recent studies have shown that
    indoor air in many American homes to be more polluted than the worst
    cities in the country. 
           
    The best solution is indeed air-to-air heat exchangers.  But
    these will at best save you only half the energy in the air being
    exhausted.  However, there costs are coming down sinifigantly, as
    shown in a recent Popular Sci article.  Calculting payback times would
    be an interesting exercise.  However, I will be content in the
    knowledge that the incompetence of my builder has insured that I
    maintain a steady supply of fresh, (relatively) clean air throughout
    my house, drawn in at every level by my equally inefficient oil
    burner.  This I can live with until I build my "dream house",  which
    will of course be totally self sufficient, relying on no outside
    energy sources, and introduce warm fresh air for ventilation through 
    a passive solar phase change heat sink system of my own design.
    
                    Well, a guy can dream, can't he?
    
    

this may be a little late, but for Owens-Corning phone number, just call
1-800-555-1212.  

-mark

    It's me again.  I still haven't done the attic: it was too hot this
    summer.  Now I have to open up the soffit vents for the heating
    season.  What do you think:  Can I get away with simply cutting
    back the insulation in the strips that cover the vents, and leave
    the others insulated all the way in to the corner?
    
    Elaine
    
    p.s. Jim: still interested in some pink stuff?

    During the winter the slider off my livingroom has an aweful draft.
    The problem is that I want to be able to open and close the slider
    during the winter, so I don't want to shrink wrap it. Can anyone
    recommend something else to use?
    
    Thanks,
    
    nancy

Hi, Nancy. How about thermal drapes?

Linas

    Well I've got quilt curtains up. The problem is around the edges
    and the amount of draft that comes in.
    
    nancy

    
    
    	Do to a lot of delays resulting from a new addition (to my family,
    not the house) I've just started hanging the rigid insulation on
    the cathedral ceiling. I still have a question on the vapor barrior
    over the rigid insulation. I checked out some new construction and
    they were not installing vapor barriors over the foil faced rigid
    boards. It would seem that with the foil face there is no need for
    an additional barrior as the foil takes care of this? Except for
    maybe seams where it might be good to tape them with duct tape?
    Should I or should I not add a poly vapor barrior?
    
    	One other puzzlement, the rigid insulation I have has one side
    where the foil face is much more shinny than the other. Is there
    a inside and out side to this stuff?
    
    			Slow but sure...
    
    					...Dave
    
    

    How about using magnetic strips to keep the edges of your curtains
    tight against the frame?  
    
    The shower surround that I put in used these strips to keep the door
    shut.  They are quite thin, so I think they could easiy be attached
    to the curtains and frames. Only problem is I don't know where they
    might be purchased. 
    

    You can get magnet strips by the yard in some fabric and craft stores.
    
    The draft around the door should also be investigated for its cause.
    Is it around the frame?  From the basement we were able to stuff
    some strips of insulation up under the door frame, reducing the
    draft considerably.  Also check to see if there are gaps in the
    caulking both inside and out.
    
    Peg

    
    
    
      Don't they sell slider storm doors. I'm pretty sure I saw one
    at Webber Lumber. They pretty much do the same thing as a good
    quality storm door.
    
    BAL

If your slider is one of those old aluminum single pane types, consider 
replacing it.  Of course it's expensive, but in the long run you save money.  
When we moved into our house, we had a slider in which you could SEE the gap 
between the slider and the frame.  It was so bad we had a half inch of ice 
caked on the INSIDE.  We replaced it, and our heating bill went down 
significantly.

If you get a good quality, double or triple glazed, or insulated glass, you 
don't really need to do anything special to it in the winter, and you don't 
get any drafts.

Clay

    No need for a vapor barrier with foil-faced insulation (or with
    extruded styrofoam, for that matter).  You do need a vapor barrier
    with the "beadboard" type of foam insulation because that's not
    impermeable, but what you have is fine as is.  Taping the joints
    might be a good idea.
    
    I seem to recall reading someplace that the reflectivity of the
    shiny/dull aluminum foil is basically the same, so don't worry
    about it.

>    	One other puzzlement, the rigid insulation I have has one side
>    where the foil face is much more shinny than the other. Is there
>    a inside and out side to this stuff?
    

Sorta.  There's a screw/nail side and an other side.  The side that is 
not so shiny should be the side with the writing on it.  If you're going 
to fasten the stuff on with screws or nails, you want to screw/nail into 
that side.  The reason it's not so shiny is that it has a mylar coating 
on it.  It will offer a (small) resistance to the screw/nail so that you 
don't punch the fastener through the board.  I found out about this the 
hard way...

As far as joints go, there is a special aluminum tape for this if you 
want to do the best job of it.  The people who make the boards make the 
tape and it's supposed to be better than duct taping the joints.  It's 
not moisture permiable, as duct tape is, and it's supposed to have 
better adhesion to the board surface.
					>>>==>PStJTT

    I installed a slider storm door.  Purchased at Grossmans four years
    ago for about $100.  It is simply another slider (single pane) with
    track system that bolts onto the outside of the existing door.  The
    tracks stay on pemanently but the doors can be lifted out for the
    summer.  It really helped out.
    
    Frank

     RE: .7
    
      Can you still use the slider???   We have a slider in our kitchen
    which is used frequently but could use the extract protection in
    the winter.  What was the brand name of the slider storm door?
    
    SD

    Yes! You can use the door very easily with the storm door in place.
    It works just like an additional screen door would in the summer.
    I don't know if I will be able to find any brand name label still
    on the door.  I purchased it at Grossman's about 4 years ago.  I'll
    look at the door tonight to see if any other name exists.

    Hi,
    
      Went to Grossman's last weekend and asked about the slider storm
    doors.  They don't carry them any longer.  No need because the current
    sliders are very efficient.  Of course this doesn't help when you
    have an older door.
    
    SD
    

    You could get a Window Quilt made for the door; they run in tracks
    at the edges and seal pretty tightly.  Not cheap though, and of course
    it would only help when it was down.  I expect the most satisfactory
    solution is to repalce the door with a better one.

    I don't know if this is any help in your location.  My brother in
    law just purchased the same slider storm door I am talking about
    at "Heckenger's".  Heckinger's is a new "Super Store of Home
    improvements" in my area.  They are plentiful in the Pennsylvania
    area. Try Channel, or other lumber/home improvement stores in your
    area.
    
    Good Luck
    

Ditto...   Just ordered one from Hechinger's myself.  They were $125, on
sale... but that doesn't mean much when you're the only game in town!

Bob

    
>>    Went to Grossman's last weekend and asked about the slider storm
>>    doors.  They don't carry them any longer.  No need because the current
>>    sliders are very efficient.  
    
    Isn't that a laugh.  As if we all have brand new houses!
    Sounds like the crap I get when I try to fix up my house...
    
    "Why don't you just replace those old wooden windows with these brand
    new vinyl ones instead of putting in weather stripping,
    
    ...and you could replace those old wooden doors with some nice steel ones, 

    ...and why don't you cover those old plaster walls with some sheetrock, 
    
    ..and why bother fixing that old boiler - the new ones are much more 
    efficient, 
    
    ...and speaking of needless maintenance, don't bother to paint the
    house, just put vinyl siding on, and never paint again..."
     
    
    Really, I kid you not.  I've heard them all!   Even if I wanted to 
    implement some of those stupid suggestions, do they think I've won 
    the Megabucks, or what?
    
    -tm
    
    p.s. Excuse the flaming, I think I've met one too many of these
         idiots.
    

    
    	What's the proper way to install Kraft faced insulation on a
    	2x4 studded wall 16" oc? The insulation is 15" wide so that
        fits nice and snug between the studs, the Kraft paper is 16
        or more inches... It seems to me that the staples should be
    	installed on the outside 2" side of the beam, others say no
    	and the paper is stapled to the 4" side. None of the how-to
    	books specify... I intend to put up gypsum board over the
        insulation. and the whole mess is being assembled in my
    	walkout basement.
    
               2x4
              | " |           | " |        |   |]         [|   | 
              |   |           |   |        |   |           |   | 
              |   |   KRAFT   |   |        |   |  KRAFT    |   | 
              |   |           |   |        |   |           |   | 
              | " |           | " |        |   |]         [|   | 
                
                " = staples                     ] = staples
    
              
              Dean
      
                

    I vote for stapling on the 2" face.  That way, you get overlap
    of the tabs, they lie flat and get mashed down by the wallboard
    going over them, and you get a tight seal.

    The argument for stapling to the 4" face is that you form a pocket,
    trapping a layer of dead air between the wallboard and the kraft face.
    This dead air provides additional insulation.
    
    Personally, I prefer the tight seal Steve mentioned in .22.  I also
    find stapling to the 2" face to be easier and neater.

	.22 is correct.  There was some wisdom in the 70's about stapling on the
	side and creating a 1/2" air gap.  In reality you have to compress
	the air out of the well behaved little pockets of air in the insulation
	and created a less efficient large column of air.  The tabs on kraft 
	faced insulation go on the 2" dimension and should overlap.  The kraft 
	face goes on the inside of the house.

	Current thinking is to use unfaced insulation with seperate sheet 
	vapor barrier.

	Brian

And, of course, if you are assembling the wall from the cold side (or
a basement floor from below or an attic floor from above), you have 
to stuff it in kraft paper first so that the vapor barrier is on the 
warm side.  In that case, the paper side tabs do have to be folded,
although I'm blessed if I can see how you'd manage to staple them.

But how do you make a tight vapor barrier in that case?  Aside from 
vapor barrier paint, which doesn't work for insulating floors.

	Larry

    Just to confuse matters (well, I'm confused anyway), we just had our new
house insulated and they stapled the paper to the 2" side upstairs and inside,
on the 6" side (2x6's) downstairs.  Hmmm.  It's not that big of a deal, as
far as I'm concerned, if I lose that 1/2" of insulation to have them come out,
rip it all off and put it back on the 2" side.
    1.  The 1/2" loss is only about an inch wide, along the stud, because the
full 3 1/2" (or 5 1/2") insulation billows out right away.
    2.  The paper stapled on the 2" side is definitely neater looking.
In 30 years, if someone rips down all the sheet rock in the house, they might
be impressed.

    
    	Thanks for all the responses,
        I'll take your advise and staple to the small face.
    
    	Dean

Attic follies:  I asked about cutting insulation in .9 and then asked (a dumb
question) about venting the soffit in .20 .  I started the project this weekend.
First, my house is a split ranch, like so:

                         
                                    ^
                              /            \
                        /         +----+         \
                  /               |    |               \
            /                     |    |                     \
      /                           +----+                           \
/     _0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_0_     \
------+                                                            +------


	 /   -  approximate roof line
	---  -  soffit with vents
        0_0  -  12" fiberglas batting


The insulation was totally blocking the air coming in from the soffit vents, 
and as a result there was lots of mildew on the roof trusses.  (I left these out
of the picture for simplicity.  I wish I could do that with the attic!)
House inspector told me to open up the soffits to fix the problem.  The problem 
was, he guessed, that the insulation was stuffed all the way into the soffit, 
like so:

              /      
	   /0_0_0_0_0_0_0_0_0_0_0
	/ 0_0_0_0_0_0_0_0_0_0_0_0
	---------+                 


The actual problem is that the pitch of the roof is so sharp that I can't 
insulate the ceiling with 12" fiberglas without blocking off the airflow,
like so:

                   /
	      /  0_0_0_0_0_0_0_0_0_0
	/        0_0_0_0_0_0_0_0_0_0
	---------+                 


I needed to cut insulation, but I couldn't just lop an even piece off the end.
I used the utility knife (thanks, .10) and cut out a triangular portion which
would parallel the roof line:

                   /
	      /     _0_0_0_0_0_0_0_0
	/        0_0_0_0_0_0_0_0_0_0
	---------+                 

It was not, of course, easy, because I had to go in 24" before I had enough 
clearance.  In this case, I don't think the large shears would've helped.  I 
did 6 sections last night before my knees got sore from the cramped quarters 
and kneeling in a fiberglas world.  I hope my attic is breathing easier today.
The rest shouldn't take me as long, now that I've got my system down.  I'm 
filling one trash bag for every two sections cut!  I hope I can use this stuff 
somewhere so it can earn its keep!

Thanks for the advice.

Elaine
    
                    

    If it's not too late, get some Propa-Vent channels.  It's styrofoam (stiff
white stuff), about 1/2" thick, and it's designed EXACTLY for your purposes.
It's shaped like:

       ______                        ______        15" left to right,
             \                      /              maybe 2" top to bottom
              \____________________/

You squeeze the bottom, flat side against the insulation, the open, channelled
side against the roof (plywood?) sheathing.  This provides air channels from
the soffit vents up toward the attic/non-insulated space, vented by gable end
louvers or ridge vents or some such.
    Yes, you'll compress the 12" of insulation to something less, but you
shouldn't have to cut any (yuck).

    Our next door neighbor just had an addition built. The builders
    used Propa-Vent for exactly that purpose. It is a great idea. Can
    you tell us where to pick up this Propa-Vent? I had never heard
    of it before and am facing the same problem.
    
    
    				herb

   Sorry.  Our insulator installed it.  I'd guess lumber yards, if insulation
outfits won't.

    Propa (sp??) vents are available at any lumber yard.  Even at 
    [[Yecchhhh!!]]  Grossman's.
    
    I take their ads as a personal affront that there's a little gross
    man in me.  Even though there is, he bears no resemblence to any
    one or thing at Grossman's.

    re: .30
    
    Will propa vents provide enough air flow?  The next question is
    will I have to nail the suckers in place?  This might be just as
    nasty as what I've been doing...
    
    Elaine

    
    They provide excellent air flow.
    
    They are made to just fit into either a 16" or 24" on ctr refter
    sytsem.  In other words "You squeeze them ever so slightly and they
    expand to hold themselves in place."

    I too think you won't need to nail them in place - the insulation squeezing
against them should keep them in place.  With (what appears to be) your shallow
roof, where are they going to go?
    I'm also not sure nailing through the crumbly (I think) styrofoam would
secure them too well anyway.

    I also forgot to mention (probably don't need to, though) that these
Propavents, as well as any between-rafter vents, should be placed in every
"bay", that is, between every pair of rafters.

    Also, also, somewhere in this conference, someone described a way of
installing insulation against roof-sheathing - with its roofing nails
sticking out and grabbing things like fiberglass batting and, uhh, Propavent.
He first slid a pair of smooth, stiff, thin material, like masonite, between
the rafters; then he slipped the insulation in between the two panels.  Sounds
like it'd work for Propavent, too.

    fyi, a 4' by 15" propavent is $.99 at Grossman's (last night). 
    I bought one to try it out.  Will report back with the results after
    the weekend.
    
    Thanks, guys (?).  I mean it.  This is gonna be a lifesaver.
    
    Elaine

    Well ? Did it work out? Don't leave us hanging .......

    I didn't get to it last Sunday.  The one I bought was the single
    width vent, which is 11 1/4" wide.  I went up Sunday to try it and
    found out I needed the double width vent, 22 1/2" wide.  It took
    a long time because Grossman's hides them up in a loft in the
    contractor's area, and no one knows the price or the code.  They
    charged $1.99 for the double width, 4' length.  I'm going to do
    it Saturday.  I expect it to go well once I get to it.
    
    BTW, a report on the previous attempt.  The six sections where I
    actually cut the fiberglas, the trusses are almost dry on the mildew.
    I guess that's a good sign.  I've also found gaps around most of
    the sill in the basement, which must account for the cold feet in
    the bathroom in the morning!  I'm going to apply the already cut
    insulation there.  Hello toasty feet!
    
    Elaine

    As far as regular aluminum foil goes...

    There is a no significant differnce in the ability to reflect heat
    by either the shiney or dull side.  The differnce of the shiney/dull
    surface is a result of manufacturing which rolls two pieces of foil
    between rollers.  The sides which are facing each other (inside)
    are dull and the sides facing the rollers are shiney (outside).
    The rollers tend to polish the foil to create the shiney side.

    I have gone through all the insulation notes and can't find an answer
    to my question so here goes. How much insualation do I need? Not how
    much would I like to have but how much does (dare I say it) the
    "building code" require? Are building codes local or federal or what?
    The reason I need to know is that my extension was built as a shell
    only by a contractor and now the local town inspector is telling me
    that I must have R-30 in my cathederal ceiling. The problem is that it
    is framed 2x8 16 on center and I already bought all the R19 to finish.
    If the town is right I suppose I could add foam or fir out the rafters
    but waht a pain.  Any guidance here would be greatly appreciated.
    
    P.S. Wher do you get a copy of the building code anyway? Is it federal
    or state ? I live in Islip, Long Island, New York.
    
    
     Bill
    

    I have never heard of the codes requiring a specified amount of
    insulation.  I would think that would be up to the owner.  If the
    person wanted to be stupid enough not to insulate enough, then he/she
    would end up paying.  I would think your R-19 would be fine, although
    more would probably help, to a point.  R-30 sounds pretty high.
     Is this normal?  Could he just be making a recommendation, and
    not a demand?
    
    Ed..
    

    Did your building inspector approve the 2x8 rafters and then
    tell you you had to have R30?
    That doesn't make sense.  If he really wanted R30 he would have
    made you use 2x10's or 2x12's.  I don't know how New York's building
    code works, but I'd bet he was giving you a recommendation and not
    a demand.
    

    For questions and comments about how building codes work, how to get a
    copy, etc., see 2929.*.

    
    
    When I built my 14X18 Cathedral ceiling bedroom, the head honcho
    at city hall approved my plans with some changes that he made,
    one of them called for R30 insulation in the ceiling, like you
    kind of hard to do with 2X8's for rafters. I used 6.5" (R-19)
    kraft insulation with shoot vents from the soffit to the ridge.
    Using R-19 was fine with the building inspector, since this is what
    really should be used with the space allowed, also at least in 
    Nashua NH, the insulation is put in after the framing is inspected
    and is covered by the sheetrock etc. when it's time from the final
    inspection....
    
    the only thing I would recommend is putting in a 3 speed ceiling
    fan as at least my cathedral ceiling room tends to be colder than
    my other rooms...
    
    
    
    Royce

    1) Building codes can and do mandate insulation.  Mass codes are
    reasonable.  You should see Vermont state codes for state-mandated
    energy efficiency.

    2) You don't get high R-values in narrow spaces with fiberglass.
    But there are many higher-tech alternatives available - usually
    as rigid panels.  I worked with some stuff once that was R-19 in
    1-1/2 inches.  I have an R-30 roof with 2*8 rafters. There's even
    room for 2" of vent space above the insulation!

    
    Put in the R-19 insulation, then get those fiberglass sheets and
    put that on before the sheetrock. Or put it on the roof before you
    lay down the plywood/waferboard. Some of those fiberglass sheets
    have a R factor of up to 10 or 15. With the combination of the 2
    you should be able to acheive R-30.
    
    Mike

    Thanks for all the info and suggestions. They did approve it with 2x8's
    and then mention the R-30 at the framing inspection. When I implied the
    level of diffuculty in puting in the graeter amount of insulation the
    inspector shrugged it off and said I would"just have to fir it out"
    (maybe he would like to come do it for me?) I have in my wiring plan
    allowed for a fan in the top of the cathedral also have more than
    adequate soffit and ridge ventilation. The framing inspection failed
    the first time because there wasn't enough and my contractor came back
    and installed two huge vents in the roof above thr collar ties.
    
    I will certainly read the suggested note . Thanks again to all, you
    have put my mind at ease.
    
    Bill
    
    
    

>    I have never heard of the codes requiring a specified amount of
>    insulation.  I would think that would be up to the owner.  If the
>    person wanted to be stupid enough not to insulate enough, then he/she
>    would end up paying.  

The problem is very few homeowners build their own houses.  If it were 
left up the builders, then there would be no insulation because it would
cut costs.  
					>>>==>PStJTT

    For anyone interested. New York has something called an "energy code"
    It is a series of formulas that take into account beleive it or not yhe
    number of degree days you need in a particular geography and alot of
    other variables like wall space amount and type of glass... and then
    determines what R values you need. The technicality I got them on is
    that my stamped and approved plans specificaaly state R-19 so they
    can't change their minds now. I am still going to research loacl
    suppliers for the fiberglass panels to add to my R-19. Thanks Agian to
    all.
    
      Bill
    

    
    I'm looking for information on thin, relatively high R-value
    insulations.  
    
    There is already a note on Radiant barriers (#2201), so I'd like
    to restrict this note to non-radiant barrier insulations.
    However, if anyone has any info to add to #2201, please do.
    
    Information that would be helpful:
    
    	General description of the product
                  
    	Product name (or names)

    	Thickness and R-Value
    
    	Where it can be purchased
    
    	Cost
    
    ------
    Thanks!
    

    Thin.  How thin?  
        
    Foam is considered thin when comparing against fiberglass, rockwool,
    or blown insulation.  When compared against radiant barriers it is thick. 
    Foam is considered high R-value when compared to fiberglass because
    it will give a higher R-value for the same thickness.
    
    There was some discussion somewhere in this conference about a plastic
    bubble wrap style of insulation which requires air space on both sides.
    Compared to "conventional" insulation it gave higher R-value for
    the space required.
    
    Do you have some kind of technology in mind and you are testing
    to see if we can figure out what you know and we don't :^)
    
   

	The fiberglass panels have a lower R-value than poly-isocyanurate.
	(5.7 vs. 7.3 per inch).  They cost about the same, but other than 
	1/4" thick the panels are harder to find.  The 1/4" panels are used
	for making heat ducts.  Poly-isocyanurate has the highest R-value for 
	non-radiant insulation.

    
    
    	I would beware of the poly isocyanurate.  I agree it has very
    high R values but two things come to mind:
    
    	1.  If you ever move with DEC and want them to buy your house
    	    they won't if they find out you have that kind of insulation.
    	2.  The poly isocyanurate gives of a poisen gas when it burns.
    
    	I used this product in my roof sandwiched between two layers
    of full 1" thick boards.  The poly isocyanate panels were 2" thick
    and had a R value of about 19.
    
    	Please excuse the above if I have poly isocyanate confused with
    another product that sounds just as hard to pronounce but I believe
    I'm correct in all the above.  Probably someone will be quick to
    correct me if I'm not.  I have no problem with that....
    
    Gordon Ripley
    

    I'd like to build a number of odd shaped panels out of foam.  Does
    anyone know anything about manufacturing foam products?  
    
    I've heard second and third hand that the process of making
    polyurethane foam is "you mix the stuff from can A with the stuff in
    can B and pour it into your form where it expands and sets.  Once it
    has cured for about a half hour, you pop it out of the form." Yea, sure.
    
    Any ideas where I can get foam-in-a-BIG-can?
    
    
    John B.

    Not exactly but.... The firm I used to work for (Tektronix) had
    a 2 part system in the shipping/recieving dept. used to make 
    foam "surrounds " for protection to ship delicate instrumentation
    A plastic was places around the instrument, they were put in a
    box, and the 2 part chemical was discharged into the box as well,
    and presto custom enclosure. You may want to call your local
    shipping/recieving dept. or even Tektronix in Bedford, (ask for
    Bob).
                                                   good luck..
    

    re:23
    
    	It depends on what you want to use the foam for. Some boat supply
    stores carry pour-in-place floatation foam. I used some once. I
    think it was around $20 for 6 cu. ft..
    
	There is also blow in place foam in a can but it's about the
    same price for only 1-2 cu. ft..
    
    	Warning: With the stuff I got, when you mix the ingredients it 
    looks like a marble cake mix. When the stuff turns all dark all of a 
    sudden, you have about 3 seconds before it starts expanding. It
    doesn't look like it's mixed but it is. Don't try to keep stirring it 
    until the marble cake mix look goes away (like I did :-).

    Gee, I wish I had read this note about 3 months ago.
    
    Anyway, I just finished talking to the building inspector in Haverhill,
    Mass.  He told me I need R13 in the walls, and R31 in the ceiling.
    
    I had a contractor put up a 16' X 32' shell, with cathedral ceiling,
    and he used the 2"X8"'s.  So, I'll be looking for the rigid insulation,
    too.
    
    Lee

    I'm in the process of renovating our bathroom, and I've got rock
    wool insulation that looks like it was blown in.  (The round holes
    are in the outside wall).  I've taken some of it out, double-bagged
    it and left it this AM for the trash.  When I left for work, he
    had taken my "normal" trash, but opened the bags of rock wool and
    left them.  Is this stuff hazardous?  Or just "building materials",
    which he doesn't have to take.  I've been using a light dust mask
    when removing this stuff, should I be using something better?
    
    (I've left rock wool in the past, and the garbageman has taken it.)
     

    Keep it wet and it won't be deadly.  It's the dust that's deadly.
    Besides, it's only deadly to people who work with it for years on end
    and it doesn't take deadly effect until about 20 years after exposure.

    But the trash truck doesn't have to take it because it is hazardous
    waste.  In Newton, Mass., the trashmen have an annual hazardous waste
    day in May when you can throw away anything.

    re .5:

	WRONG!! WRONG!!! WRONG!!!!

	Rock wool DOES NOT contain asbestos.  I just called the EPA
	and they said no.  A co-worker had his rock wool tested for
	asbestos, and there wasn't any.  The dictionary defines
	rock wool as "an insulating material made by blowing steam
	through molten siliceous rock."

    
    re: .5 and .7
    
    I believe rock wool is usually made of iron.  It certainly isn't
    hazardous waste.  It's insulating value is quite good (better than
    ordinary fiberglass).  It's also non-flammable like fiberglass.
    
    -tm
    

re .8: "made of iron"

Are you thinking of steel wool?  Steel wool is flammable, and I'd think it
would make a poor insulator (metals conduct heat well).

    
    Re: .9
    
    No, I'm not thinking of steel wool, but I think it is made from
    some type of iron.  Certainly not pure or it would conduct.
    I'll see if I can find some more information on it.  At any rate,
    I know that it is not flammable.
    
    -tm
    

    Rockwool is also the root-retaining medium used in hydroponic
    gardening.
    

Isn't it manufactured by RockWool, International?

    Does anyone know anything about the blown-in insulation?  I am
    specifically interested in the kind that hardens after it has been
    blown into the wall.  This is sold in cans for doing around windows,
    doors, and the like.  It would take alot of cans to do a house,
    so I was wondering if there was some kind of bulk installation method.
    
    I like this concept because I would be fairly certain that it wouldn't
    settle, as I have heard other insulation does.  And I really hate
    to lose my plaster walls to do insulation.  I want to do wiring
    later, also.  But, I think I can do most of that from the attic
    and basement.
    
    Is there any information about this out there?  Also, does anyone
    have any idea about costs?
    
    Ed..
    

    It used to be available only commercially for the whole house.  There
    were some concerns about formaldehyde poisoning.  I do not think it is
    still available.  If you have the stuff in your walls, you will not
    ever be able to run wiring in the future. 

    Also, if you are using the stuff in the cans, be careful around
    windows and doors. Some of it will expand so much it will push
    doorjambs out of line causing them to stick.
    
    Guess how I know that :-(
    
    John H.

    I believe .14 is confusing UFFI (Urea-formaldehyde) with some newer
    stuff that comes in cans.  I don't believe the stuff in cans is
    the same -- in fact, I think UFFI is illegal now.

    
    Re: .13
    
    I don't know if this stuff is available for the whole house,
    but there a couple of big disadvantages as I see it:  it's
    flammable and the problem with wiring mentioned by .14.  I think
    if you used the modern fiberglass ("Insulsafe") it would be
    less likely to settle than something like cellulose.
    

     re .13 and .17 [speaking from direct personal observation in three
houses]:

     Blown in cellulose insulation does **NOT** settle.  Anybody who says it
does has never taken a wall down that's had it.  My current house was done
more than  five years ago and the stuff is exactly where it was when it was
blown in.

     I suppose if the installer doesn't blow in enough, it could settle.  
Thats a quality-of-installation issue.

     It *WILL* settle if you get it soaking wet, like if a pipe breaks in the
wall.  However, settling due to vapor penetration and condensation is a myth.

I believe it has alot to do with the pressure it's blown in at. 
My parents had a 3 family rental property done a couple years ago 
and I happen to be there while it was being done. In some spots 
in the basement, you could see some of the insulation filling in 
cracks in the subfloor as they were pumping it in. 

As an aside, the contractor ended up using twice the material he 
estimated he would. Didn't realize the house had balloon framing 
until it was too late. It was really toasty in the winter 
time....

daryll

    I'm getting ready to finish the upstairs on my house which includes
    two bedrooms, one on each side of the bathroom.  I want to insulate
    the noise coming from the bathroom from the bedrooms. What is the
    best type or way to insulate the noise.  I'm not worried about
    insulating for temperture reasons.
    

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DCL [Moderator]

    	The between-rooms sound barrier quality of a material or
    construction is called its Transmission Loss.  As stated, it is
    a function of the weight of the material, and it's internal damping.
    For a construction, its also a function of the decoupling of the
    elements to prevent structureborne noise transmission (flanking).
    	The important thing to remember is that if you don'd decouple
    before you add mass, you only improve the TL by 20 log weight: 6
    dB for every doubling of weight.  Say you had a wall of 10 lb/sq.ft.
    density.  Say that wall gave you a TL of 30 dB.  If you added another
    10 lb/sq.ft. right on top of that wall, you'd only go up to a TL
    of about 36 dB.  But, if you decoupled the added mass by using
    resilient channels to space/isolate the new mass, you would be adding
    much more than 6 dB to the TL (not as much as another 30 dB, but
    something in between).   It's kinda like layering cloths - a few
    independent layers work better than one thick heavy layer.
                - Chris

Balloon framing means that the studs go straight up from the sill to the
roof, instead of being interrupted by a platform at each floor, as in
modern platform framing.  As a result, unless you deliberately block up
the spaces between the studs, anything you drop into the wall below the 
lowest firestop will fall (in my case) right into the basement.  In the
case of .-2, I gather that there was a basement ceiling, so the excess 
material went to insulating their ground floor.  Sounds warm!

	Enjoy,
	Larry

    In case it's not generally known ....
    
    	Balloon framing = fire hazard too
    
    The absence of any fire breaks in the walls, or at floor levels will
    allow a chimney effect in the event of a fire. The result is usually
    very rapid spreading of the fire, possibly resulting in complete
    destruction of the structure within something like 30 to 60 minutes.
    
    We had a house in our neighborhood with balloon framing which burned.
    By the time the fire trucks arrived there was hardly anything left
    to save.
    
    FWIW
    

    
    Can you buy Tyvek (or similar product) in quantities less than a full
    roll ?
    
    I just need about 20 lin. ft. for a patch job. 

RE:  Canned Foam Insulation a few replies back.

	The canned foam insulation is not formaldehyde based.  The material is ]
a two part solution that reacts when exposed to air to expand and harden.
The material is similar to the ureathane used in extruded ureathane insulation 
panels, and must be covered because it is flameable.

	The material is also available in bulk through contractors. Whole house 
applications are not a do it yourself projects.  For large applications the 
contractor uses a special applicator that mixes the chemicals which are stored 
seperately.  The applicators are 15" or 23" wide with flanges to position the 
applicator at the right depth for 4" or 6" walls.  

	Someone said that you can not run wires after insulating.  Actually, 
depending on codes you can run wires and have a better insulated wall then 
with fiberglass.  A channel is cut into the expanded foam where the wire will 
run, then the channel can be refilled after the wire is run using the small can.

	One of the bad points about using this stuff is that it can get messy.  
The directions warn about skin contact("AVOID SKIN CONTACT.  IN CASE OF SKIN 
CONTACT DO NOT USE SOLVENTS.  NO SOLVENT WORKS ON UREATHANE").  I learned about 
how serious the manufacturer is last weekend.  A can I was using developed a 
leak and spraid foam all over my stomach.  The only way to remove it after it 
hardens is to sand it off.

Brian

I'm pretty sure you can't buy a part-roll.  I have what might be 20' of
Typar (I think) that is similar.

(I tried sending mail, but couldn't connect.  I work in ZKO, and live further
north.  Let me know.)

    Does this mean it is appropiate to put it between the fiberglass
    wall insulation and the blue board. Adding R-14 to R-19 seems pretty
    attractive.

    
    RE: .18
    
    You can put reflectix against the fiberglass, but you should have
    an air gap (using furring strips, usually) between the reflectix
    and the blueboard.  The recommenced air gap is 1/2", but I would
    think even a small air gap (~1/4") would be pretty effective.
    

    
    
    	I am going to "gut" the upstairs, there are 2 bedrooms up there
    	now with very little insulation. I want to make bigger closets
    	and do a complete insulation job.
    
    	My question is this, I have heard that it is best to put those
    	little round air baffles I guess you'd call them, under the outside
    	gutterings to allow the insulation and whatever to breath. Any
    	truth to this?
    
    	

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Paul [Moderator]

    Update to .10
    
    Last week, my son was home when the inspector came for the rough
    framing inspection.  When I got home, my son had a note that said,
    "Walls, 19, ceiling 40".
    
    I said, what is this?  He said that's what the inspector told him.
    
    This morning I called the inspectors office, again.  Now, he tells
    me that it's 11 in the walls and 30 in the ceiling, but 19 in the
    floor if the basement is unheated, which is what I'm having.
    
    So, to date I have R11, R13 and R19 for the walls, and R30, R31
    and R40 for the ceiling.
    
    I don't intent to go just to code, but I would be nice to know what
    the minimum is so that I'm sure to surpass it.
    
    Lee

    Minimum recommendation was: R-11 walls, R-30 ceiling, R-19 floor.
    
    I think this changed recently; this week's Globe had several
    articles on insulation.

    I'm about to install some of the rigid insulation to my new cathedral
    ceiling.  It's stated on the insulation that a 3/4" spacing is required
    in order to achieve the full R value.  
    
    Does anyone know what R value I'd get if I had 3 1" layers of this,
    back-to-back-to-back?
    
    And, instead of nails or screws, can I use some adhesive to stick
    one sheet to another?  Or hot-melt?
    
    Lee

    
    	I'd suggest calling the manufacturer.  They should be able to not
    only give you the effective R values, but also suggest the best ways of
    fastening them together.
    
    	At a minimum to help, we'd need to know what kind of insulation it
    is.
    
    								-craig

    Seems like a good place to ask this:
    
    I've an addition to my home.  I've got some interior walls that
    I want to insulate, for noise purposes only.  I want to use R11
    unfaced.  But, as I'm probably having someone come in to put up
    blueboard and plaster, these walls are just studs at this point.
    
    Question:  If I put in the insulation now, what can I do to keep
    it in place until the blueboard is installed?  I've already insulated
    the old exterior wall for noise, but the opposite side is in place
    and the insulation stays where it's put.  
    
    Any ideas?
    
    I've thought of using masking tape.  Anyone see a problem with this?
    
    Lee

    Why bother with unfaced insulation?  If you don't want a vapor
    barrier, just slash the kraft paper facing with a razor blade.

    I just insulated my garage ceiling...cuz we up a bedroom above. I used
    R-26 unfaced "attic blanket"...To keep it up there until I put up the 
    5/8" fire board , I used "insulation rods" that I purchased at
    Somerville Lumber... They are "coat hanger" thickness and come in 16
    and 24 inch for whatever your studs OC are...A box of 100 was around
    4.00 if I can remember...
    
    After you put the roll up just take a rod and insert it in between
    the studs. The ends are inserted next to the edges of the stud and the
    middle bows in to hold the insulation in against the back side of the
    wall...
    
    
    
    						good luck.........john

    John, sounds good.  
    
    How far did you space them for the ceiling?   I've got to insulate
    my floor with at least R19, and haven't used these rods.  Is there
    a recommended spacing for both ceiling and walls?
    
    Lee

    I put them every 3 ft or so...I think the package had a sticker on it
    that noted how to space them...I did 20 rafters 22'  long and only used
    one package..
    
    
    						john

    Thanks, John.  I'll pick up some tonight.
    
    Lee

    This is in reply to an old note -- but I think it is still pertinent--
    My next door neighbor here in Colorado Springs is a Fire Inspector
    Arson Investigations and he advises that "ALL" repeat "ALL" building
    materials give off deadly poisonous gases when burned. So I am
    referring to the last -.1 note warning about DEC being upset if you use
    a certain material in your building as being a way out for them if they 
    were looking for it..  Why would DEC pick on certain materials when all
    are equally deadly???    <DICK>

>    My next door neighbor here in Colorado Springs is a Fire Inspector
>    Arson Investigations and he advises that "ALL" repeat "ALL" building
>    materials give off deadly poisonous gases when burned. So I am
>    referring to the last -.1 note warning about DEC being upset if you use
>    a certain material in your building as being a way out for them if they 
>    were looking for it..  Why would DEC pick on certain materials when all
>    are equally deadly???    <DICK>

Ask your neighbor again if he said all gases are EQUALLY deadly.
Surely this is not the case.
Yes, in a fire the superheated gases, even the ordinary air itself,
can get so hot that the lungs of anyone breathing them would be 
fatally seared, but that's just one of the hazards.
The POISONOUS content of the fumes will certainly differ in strength,
toxicity, volume, and duration based on the source material,
as will the likelihood that the material will burn in a given instance,
such as a localized kitchen fire versus a whole-house conflagration.

I'm not defending the stand that says DEC would or wouldn't participate
in a home buyout deal in such an instance, just saying that the stand
isn't immediately dismissable from either side.

- tom]

With the winds in New England last night, I found that the center of my
slider whistles!  Not much air coming in but the noise gives me and others
the chills.

BTW, by center I mean the joint (vertical) between the two segments, the edges
seem to be ok. Window quilts might reduce any draft but I'm more concerned
with the noise.  Any suggestion a little more elegant the duct tape
would be appreciated.  I'd also like to be able to still use the door since
the gas grill is on the deck.

Thanks, Ray.

    
    I would find the manufacturer of the door and get a new seal. Suree,
    you can jury rig something on the outside of the door with sticky foam
    tape, but the right way to do it is to replace the worn out seal.
    
    CdH
    

    
    
    The stationary door of our slider is not fully seated in the
    door frame. This causes a mismatch at the seam where the two
    doors meet. I'd like remove the door and reseat it, but could'nt
    figure out how the door is held in place. Can anyone offer any
    help.
    
    
    Steve

    Not that this belongs here, but for lack of a better note, and time...
    
    I recently finished remodeling the kitchen, from wiring to plumbing,
    etc.  I've got outlets along the countertop, which is along an
    exterior wall.  After putting up the wallboard, I had to move a
    couple of outlets, thus, there's very little, if any, insulation
    behind the boxes, and the draft through the outlets is tremendous.
    
    What can I put in the outlet boxes to stop this draft?  I know MASS-
    SAVE has foam-type cut-outs that you can install, but to get them,
    I'll probably have to pay for an energy audit.  Where else can I
    buy them?  Also, I haven't done it (yet), but if I stuff pink
    fiberglass in the box, that's a potential fire Hazard, with hot
    wires in the box, correct?
    
    Thanx.
    

Looks like the right place for this question to me...

The foam-type cut-outs are readily available at hardware stores, in the 
weatherstripping-and-insulating-materials department.  Ask for "those things 
that stop drafts through my outlets".  They're less than a couple of bucks for
enough pieces to do a dozen outlets and switches.

    Another option is to inject some of the aerosol "expanding" foam insulant
    around the outside casing and in back of the box.  The foam kits
    come with a plastic wand (straw) to make injecting into wall cavities
    easy.
    
    It is super sticky stuff and does expand CONSIDERABLY so use with
    care.

  I'll be insulating a ceiling from the warm side. i.e., when you look up,
you'll see the ceiling joists, and above that the roof structure.

  So, is the only method to insulate in this application to use Kraft faced
faced fiberglass insulation, since the insulation will need staples to be held
in place?  OR is there a way that the unfaced/plastic sheeting route can be
taken?

  Which is better for this application?

  Steve

  

    RE: .-1
    
    You can use either method.  It would be easier to use the plastic IF
    you can get above the ceiling to install the fiberglass bats.  If you
    can only get at the ceiling from below, then you're stuck with the
    faced insulation.
    
    Dan

  I am a homeowner-to-be, and (embarrisingly) am not a construction expert.
I am trying my best to sound knowledgable with the builder, and am going
through the anxiety of listening to them tell me everything they are doing is
right, although I know it isnt-but-I-can't-be-sure, etc.   Maybe you can 
help me:

   In particular, I was convinced by handyman friends with more experience 
to go with TYVEK for outside insulation.  The company usually uses tar 
paper, but they agreed to do it as an option for just the cost of materials 
($200.00).  They are wrapping the perimeter of the house except the garage, 
and need a height of 18' (two stories).

Situation:
       Friends told me that two 9' rolls would be the best, but the company
       and I signed a contract for 5' rolls.  At the site yesterday, I 
       discovered that they are using 3' rolls of TYVEK and the way they are
       putting it up is by cutting it into strips (size of tarpaper each) then
       are overlapping the strips by 2" and are stapling it down.  They they
       then are nailing the vinyl siding on top of it immediately (not 
       hammering the nails in all the way, which I read earlier was good).
       They are not using tape on the seams.

Q:     What is the proper size/procedure/etc. for installation of TYVEK?
       Has the builder ruined the purpose of TYVEK by overlapping and stapling
       in small strips?   

Q:     The contractor's told me that their supplier only had 3' rolls, because
       they felt that this size was the best in their opionion for insulating
       but it let the house "breath" without too much of an R factor.
       They also told me that it shouldn't be taped.
       Is this bull, or is their some truth to it?

Final notes.  The windows are already up on the frame.
	      The entire house is surrounded by partical board.
              The house is using a triple E insullation package, with
                walls=R-19+, ceiling, R-30.

Thanks for any assistance,

Ken Rosenberg (novice and anxious).

    You are defeating the purpose of Tyvek by cutting it up.  Might as
    well use building paper which is a lot cheaper.   Tyvek is sold in huge
    9'x190' rolls so it can wrap an entire floor with only one seam.
    

Previous response was correct.  Also, it should be installed before
    windows and doors are fitted.  The Tyvek should be wrapped around
    onto the inside of framing opening (sort of like gift wrapping).
    And any seams should be taped.
    
    Concord and Littleton Lumber provided me with the 9' rolls.  They
    also publish a monthly newsletter for their "contractor" customers,
    which usually offers some good product information.  I remeber them
    doing an article explaining the Tyvek product and its proper
    installation.  You might stop by their Concord or Littleton stores
    and ask for a copy.  It would support your argument against the
    strip installation your builder did.

    I beleive there is another process. Check out your local lumber
    store for some metal rods used to hold up insulation.
    
    The 1/8" rods are pliable and cut to fit in between the joists.
    Just push in place under the insulation and they bend and hold
    the batting strips in place.
    
    I don't remember the price but I think it was real cheap for
    a bunch of them.
    
    Good Luck! 

    One more thing Tyvek is not insulation it is an air infiltration
    barrier. It is designed to allow water vapor to excape and slow the
    exchange of air. As said earlier Cutting it into small strips to let the
    house "breath" is not necessary because that property is already 
    built into the Tyvek.  
    I don't remember ever seeing Tyvek in 3' rolls but I have not needed
    any in a couple years. Are you sure it's Tyvek they are putting on?
    I have see open cell poly insulation in 3' rolls used under siding?
    Tyvek (brandname) is stamped all over the stuff can't miss the name,
    and it's just about impossible to rip a piece in half by hand.
    
    (BTW if it's Tyvek and the builder can tear it refer to him has sir
    ^:-) 
    
    Don 
    

    I'm pretty darn positive it's Tyvek.  (It says so all over the sheets).
    Just to make sure, I'll try to rip some of it today!
    
    From what I'm hearing, should I tell them to scrap the Tyvek and go
    back to Tar Paper, or threaten them with the Better Business Bureau for
    not using material properly?   And why would 3 foot rolls exist, unless
    they had some purpose? (other than doing Doghouses :-)).
    
    What about if they tape the Tyvek seams?  Might this still be better
    than tarpaper for slowing the exchange of air, and the vapor barrier?
    What kind of tape should they use?  If they taped and overlapped, 
    wouldn't that still work? 
    
    That's 6 questions, so I'll stop there.  I didn't know that buying a house
    could be this much fun!
    
    Ken

re                   <<< Note 1696.42 by WMOIS::G_PELLETIER >>>

   Good info!  

   But, since I plan to sheetrock the ceiling after insulation and rough wiring,

   Are you supposed to put up strapping perpendicular to the joists for the
   sheetrock to be screwed into?  Or do you attach the sheetrock directly to  
   the joists?  

   The reason I ask is, if the answer is yes, then the strapping would serve
   a dual purpose by also holding the insulation up, I'd rest the sections
   on insulation on top of the strapping in between the joists, then sheetrock
   below it.

   Is the right, or would I flunk Sheetrocking 101?

    Strapping is not required if your joists are not more than 16 on
    center.  
    
    The little wires are cheap and a breeze to install if you go that
    route.

    I seem to recall that Concord Lumber's article on Tyvek referred
    to a special Tyvek tape.  Don't know whats special about it.....
    probably just the $ and it says Tyvek on it :-).
    
    The 3 ft. rolls were just introduced about 2 years ago.....they
    are targeted at small additions and remodeling.  The focus being
    sq/ft per roll not 3 ft. vs. 9 ft.  Also, alot of contractors
    prefer working with the 3 ft. roll. You can imagine how "easy"
    it is to unroll a 9' roll while up on a ladder!!!

    RE: .-2
    
    For the cost of the strapping, I would install it.  For one, it will
    make the installation of the insulation easier.  Number two, it will
    also help to prevent the joists from moving.  In the house I am
    building now, I have both bridging and strapping.  My floor won't
    squeak.  If you do decide to install strapping, double nail at each
    joist using 6d nails.
    
    Dan
    

     First of all, thanks for your many (and varied) responses.  

     Second of all, there certainly was alot of controversy over all of
     this, so I decided to contact the horses mouth, if you will, and
     called DuPont today.  (After all, I live in Delaware, DuPont's 
     headquarters.)    I spoke to general information who directed me
     to Tyvek product information, who referred me to a Textile Fibers
     "expert"  specializing in Tyvek for house insulation.

     Her opinion of things was that as long as the construction crew was
     overlapping the Tyvek by 2", then everything would still work just
     fine, even without taping.  She thought that the only disadvantage
     to this was that the crew was making more work for themselves by using
     small strips, and that usually, the Tyvek is rolled out as long as
     possible before cutting.

     She also she said that DuPont recommends 3M Y8086 tape to cover seams
     I forgot to ask her what kind of tape this was.  At any rate, she
     assured me that even without taping, the results would be much better 
     than using tar paper, and that Tyvek is *really* a great product anyway, 
     so buy lots of it.

     After hearing this, I decided (as a homeowner in progress) that her
     opinion is the only one that counts, and that all other opinions so 
     far received were only a sadistic attempt by experienced HOME_WORKERS
     to make me feel bad, and then snicker behind my back after I leave 
     the conference.  No, seriously, I agree that the best way to do this is
     with the 9' rolls, tucking in windows, etc.   Unfortunately, I get what
     I get by this builder, but it may not be all that bad.

     An archetect friend of mine also reiterated with .3 that Tyvek is 
     really icing on the cake, and may not really be that important in the
     scheme of things.   At least with all of those staples, perhaps one or
     two may hit the studs that got missed by the framers :-)
     
     Thanks again for all the responses.  I'm getting more info on Tyvek
     mailed to me.  I'll post anything interesting.

Ken

 

    Steve, I'd go with the faced insulaltion and staple to the joists,
    rather than use the metal rods, simply because the rods end up
    squeezing the insulation, thus reducing it's R value.  Then, put
    up strapping on the joists.  This will increase your insulation
    factor somewhat, as it will create an air gap.  Air is a great
    insulator, too.  
    
    I just completed doing a cathedral ceiling, where I did as above
    with the fiberglass, then added two layers of solid insulation.
    The manufacturer indicated that the R value of the solid was much
    greater with a 3/4" air gap between it and whatever you add it too.
    Without the gap, it had a value of 7, with a gap it was 9.2, I believe.
    For the cost of strapping, it's worth it to get the increased value.
    
    Also, the joists may not be level.  When you add the strapping,
    you can shim to level out the ceiling.
    
    Good luck.
    
    Lee

    "with all those staples..."
    
    Whoa - now there's something you should look into.  Every staple into
    an infiltration barrier (or an indoor vapor barrier) puts two holes
    through which the phenomenon you are trying to prevent can get through!
    
    Tons of staples can add up.  Tyvek and polyethelene should be installed
    with the bare minimum staples necessary to hold it in place.  The
    installation of the finish material will put in enough nails or screws to
    ever keep it from shifting.

    	If you are doing you own electrical wiring, I've been told that
    installing strapping makes the job MUCH easier - many less holes to
    drill. 
    	I'm coming up on this stage so I would appreciate hearing about
    this from those who have done it. - Chris

    RE: .-1
    
    I am still working on my new house and did the electrical in December
    (BAD TIMIMG!!!)  What you recommend might not be up to code, check with
    your inspector.  Besides, its easier to drill a few holes than to
    staple the wires to each joist.  When drilling, use a Nail-biter (tm)
    bit.  These bits are usually 18" long and go through wood like a hot
    knife through butter.  A 1" bit will give you enough room for 4-5 #12
    wires. The holes should be roughly in the center of the joist.
    
    If you are also wondering about how much wire, try to over-estimate. 
    In my 4-bedroom colonial with an oversized 2-car garage, I used about
    3500' of wire.  I also got my wire from a wholesaler.  The price is the
    same as anywhere else, but the quality is much much better.
    
    One other thing to check,  I used a modified wire nut known as a
    "Greenie" for the ground wires.  Basically what this is is a wirenut
    with a hole in the e.  All but one of the ground wires are cut to
    length.  The last one is left long.  Twist them all together, and
    thread the long one through the hole, twist the nut tight and:  Voila,
    your done!  Great time saver.
    
    Dan

    Two things -
    
    My house has strapping for the ceiling blueboard; the electrician
    ran his wires over the top of the strapping (at right angles to
    the joists, obviously).  This passed local inspection so I guess
    it was permitted, but I'm not sure I like it.
    
    Placement of holes in a joist SHOULD be such that the hole is
    not on the diagonal from the upper end of joist by band joist
    to the lower end by the center beam.  This is the area of
    maximum stress and drilling in this area is NOT recommended (I
    think this is even in the NEC).  Drilling in the center is only
    a problem near the center of the span.

    Question on insulating a basement:
    
    If you are going to build stud walls NOT in contact with the cinder
    block basement walls and insulate and vapor barrier those walls, should
    the insulation stuffed in to the sill area (not in contact with the
    basement walls have a vapor barrier or not?
    
    Primary purpose of insulating around the sills is air infiltration, but
    there is also some insulating value.
    
    	-Barry-
    

    We are considering buying a 100yr.old house. The present owners (8yrs)
    have suffered domestic meltdown. Ex-wife and teens occupy. It needs 
    everything. I will be reading ALL of the HOME_WORK notes.
           The clapboards are practically bare wood. Owners had cellulose
    blown in four years ago. They (thru broker) were not able to answer
    any of my other questions about the insulation(who, R rating, etc.)
           The holes made in the exterior are still open and the clapboards
    were not repaired. Plaster,lath and interior paint look OK. I doubt
    they used vapor barrier paint.
           I expect it could cost $5-10K to get the existing exterior
    repaired, and painted. We will not be doing it ourselves. I am very 
    concerned about the cellulose insulation and moisture. I don't want
    to spend all that money and have the paint peel. 
           Is there any way to remove the cellulose (suck it out ?) That
    seems like it might be more expensive than vapor paint. But paint 
    sounds like a "cheap" fix for a bad choice in the first place. If we 
    need to have lots/all clapboards replaced that will solve the problem,
    but we would prefer to restore rather than replace.
    
    hope its not necessary
    
               

    Let me see if I have this straight: they had insulation blown in to
    a house sided with clapboards, and they left the holes open?

    Maybe one of those monster vacuum cleaner trucks could suck it out.
    If it's really wet, even that might be a problem.

    Reminds me of the sales spiel delivered by a blown-in salesman.
    He said if (insert unlikely condition here) happened, they'd
    replace the insulation for free.  When I asked how they'd get
    the old insulation out, he had no idea.

    There's a house near mine that had cellulose blown in last summer.
    Like mine, it's sided with shingles.  When we had insulation blown in,
    the contractors removed shingles, cut holes in the sheathing, blew it
    in, covered the holes with tar paper, and replaced the shingles.
    Our neighbor's contractor cut holes right through the shingles, and
    put some kind of light-colored patches over the holes.  The only
    explanation I could come up with is that they were planning to re-side
    the house (though the shingles seem to be in good shape, and they don't
    even need painting).  The patches are still there.  Any suggestions
    as to what's going on?  

OK, I give: why would someone want to remove cellulose insulation
from the walls?  If it is wet, won't it dry out?  (No vapor barrier).

	Thanks,
	Larry

    Yes, I suspect it is wet, or has been. Installation holes (outside)
    have been open for four yrs.,and no interior vapor barrier.

>                       <<< Note 8.32 by VAXRT::HOLTORF >>>
>                              -< Think it's wet >-
>
>    Yes, I suspect it is wet, or has been. Installation holes (outside)
>   have been open for four yrs.,and no interior vapor barrier.

    It may be worth your while to strip a small section of wall and pull 
off the sheathing.....if it has been wet for 4 years, you may have some 
horrendous damage inside the walls. Studs that are rotting, sheathing that 
has disintegrated or is delaminating if it was plywood.....Dryrot is a 
misnomer, it needs moisture to work, and once working, can do an incredible 
job on everything......You might need to strip and re-sheath/reside the 
entire structure to stop the damage....And if the blown-in insulation is 
wet, you probably aren't going to suck it out, it will cling like wet lint 
in a washing machine.

    Sorry to sound so pessimistic, but having had to reside 2400 sq ft of 
clapboard once on my house, mostly to replace and repair sheathing that had 
gone to hell due to water leaks around the trim makes me very leery of 
water damage......

    If you find a lot of damage, it may be well to consult your lawyer 
about hidden damage claims. Particularly if it was misrepresented to you 
about how long the holes were there,etc.....

    Vic H

    RE: Base  note discussion of this problem....

I just re-read the base note to this question...You have not bought this 
house yet!!!!! GREAT!!!!

    RUN, DO NOT WALK AWAY FROM THIS ONE........unless you get it for about 
1/2 list price, and then plan on rebuilding the outside as I discussed in 
the previous note. If they did this kind of incredibly stupid trick of 
leaving the holes open, I/we can only imagine what other kind of dumb 
things they may have done that you don't see yet.....

    Vic H

    
    
    We will look very closely for any damage from insulation before we
    make an offer. We're old-house savvy having "rebuilt" one already.
    We are estimating $ to repair major problems and deducting from 
    asking price. It is way overpriced. On market 18mos., 4 offers
    withdrawn after inspection. The owners don't have the "resources"
    (financial or otherwise) to repair then sell. May be ready to face
    reality.
              I just wanted to confirm that this situation could cause
    structural damage. We will get a "professional" opinion to beat them
    over the head with.
                          Thanks!
             

    I have to replace all the 40-year old, rustic clapboards from
    my house because they're rotted out (but that's another story).
    The replacement siding will be red cedar clapboards over Tyvek.

    There's only about one inch of mineral batting insulation, no vapor
    barrier, in the walls, and I'd like to do better.  Where this stuff was
    used behind the knee wall, it was hanging loosely, so I expect that
    it's not fastened too well in the wall cavity either.

    If I try to blow insulation in through just the standard couple of
    holes, will the existing batts bunch up and prevent the gap from being
    filled?  Obviously, more holes would help, but how many are enough?
    I guess my only recourse for a vapor barrier is a vapor barrier paint
    on the inside walls, huh?

    An second alternative is to take off the sheathing to get to the
    wall cavity, rip out the mineral batts, put in a poly vapor barrier,
    install fiberglass batts, and replace the sheathing with plywood.
    There're a few windows and a chimney that the existing sheathing hides
    behind, so this isn't quite as straightforward as I initially believed.

    Another alternative is to do nothing about the insulation.  The inside
    of the wall is lath and plaster (not back-plastered).  Is the reduction
    in heat loss or improvement in comfort sufficient to make this
    worth-while?  I plan to stay in the house for a long time.  The vapor
    barrier paint might still be a good idea.

    -- Kenny House

Is making the wall an inch thicker an option?  You could mount foam
insulation panels against the outside walls.  Obviously, you'd have
to do something odd around the chimney, and you'd have to extend the
framing around your windows in some fashion.  I've seen this done,
although with vinyl siding on top, rather than wood siding.

I'm considering putting up a layer of foam insulation when I eventually
have to replace the siding.  Of course, the windows are in poor enough
shape that I wouldn't mind replacing them entirely.  The advantage of
foam insulation is that it covers the entire wall surface with no gaps,
unlike insulation between the studs, which may have gaps, not to mention
that the studs themselves are gaps of significantly reduced insulation.

	Enjoy,
	Larry

    re .1 - foam insulation on the outside of the sheathing ...
    
    I thought of that for a while, but was concerned that the
    aluminum-faced foam insulation would act as a vapor barrier -- on the
    outside of the wall.  That may not be too bad if there's a decent vapor
    barrier on the inside, but in my case it's zilch.
    
    -- Kenny
    

    My choice would be to pull the sheathing, put in fiberglass batts,
    and replace the sheathing.  Since you're replacing the clapboards
    anyway, I think this would be your best solution.  Not necessarily 
    the quickest or easiest, but the best in the long run.
    Now, you say you'd have problems around the windows and chimney.
    I can't imagine that they would be insurmountable, or all that bad.
    Of course, I haven't seen the place.  Realize that anything you
    do is going to be work, and think long-term quality rather than
    short-term expediency.
    
    You'd also have a *great* opportunity to look inside the walls and
    see if anything is beginning to rot, if you have insect damage,
    etc.

    P.S. I'd try to keep the existing sheathing.  Why spend the extra
    bucks for plywood?  

    Also, while the sheathing is off, it is a good time to put in those
    extra outlets you need. 

I'm sure there must be a solution to the vapor barrier problem for
foam insulation, since it is most often put up (I believe) to retrofit
houses that weren't originally built with vapor barriers or even
insulation between the studs.  

I expect that one could put small holes through the insulation -- if they
are small enough, they won't seriously affect the insulation value but
would break the vapor barrier.

It is hard for me to believe that it would be a good idea to rip the
walls down to the studs from the outside if there's any reasonable
alternative.  

	Enjoy,
	Larry

    For what it's worth, somebody in Bolton did exactly this -- insulated
    from the outside -- last year.  I drove past every day, and watched
    them as they took off the sheathing, put in fiberglass insulation,
    reinstalled the sheathing, and finished with new clapboards.  They
    seemed to keep track of where the sheathing boards came from, and
    put them back where they came off.  If you're taking off the
    clapboards anyway, taking off and reinstalling the sheathing should 
    not be a big deal.  The most time-consuming part of the job will be 
    putting the new clapboards on and painting.

    Re .45..49:
      Strapping works great if your joists are laid unevenly or are of
    different size -- in my case they were taken from an old barn, and
    trying to drywall under them would have taken tons of joint compound,
    if I hadn't used strapping along with shims between the strapping and
    the joists, to even things out!
    
      I'm really surprised any inspector would let you run romex through
    the gaps between the strapping. Sure you don't lose joist strength,
    but without using conduit, one of those many drywall nails or screws
    can reach the conductor and cause a short, shock, fire, or at least
    leave you with a real mess on your  hands. I always try to center a 
    1/2" or 5/8" hole in the joist far  enough away that a #16 can't 
    reach it. Of course you can't do that in a 2x4, but its the drywall 
    nails/screws that are used in bulk and most likely to come across 
    your wires.
    
    Buy that drill bit. it helps!
    

    I'm sure someone has guessed this before, but if you have a radon
    problem, won't that nice Tyvek seal help keep the bad air locked
    inside your house? Maybe you want to wrap the bottom of the house too, 
    and vent your basement!
    

    Seems to me the cable would simply be displaced by the screw; the
    weight of the cable shouldn't be sufficient to keep the cable on
    the screw to allow penetration.  Laying cable over the strapping
    seems pretty common practice in the NE area.
    
    Speaking of holes in joists (.-1), you really should use the metal
    guard plates which you nail on the joist over the cable so there is
    no chance a mis-placed screw or nail will hit the cable.  AND also
    follow Code as to where NOT to drill joists.

    Can anyone provide the calculations required to determine heat loss
    through various exterior surfaces.  I'm trying to determine what sort
    of payback I'm liable to get by ripping the sheathing off my walls and
    adding fiberglass insulation inside (see Note 3746.*).  I assume the
    caluclations are different for winter heating and summer cooling.
    
    What I envision is something like ...
    
    	Fnw(<north-facing wall area>,<R-value>) +
    	Fng(<north-facing glass area>,<R-value>) +
    	Few(<east-facing wall area>,<R-value>) +
    	.
    	.
    	.
    	Fc(<ceiling area>,<R-value>)
    
    where the "Fnw" are functions of the two arguments (area and related
    R-value), which I'm guessing is proportional to area/R, and the
    proportion differs depending on orientation (north, east, etc.) and
    whether the surface is vertical or horizontal.
    
    For summer cooling, I guess one has to consider the amount of shade
    provided.
    
    I'll try to find the "From the Walls In"  book mentioned in .1.  If I
    find anything there, I'll post it here.
    
    Thanks,
    
    -- Kenny House

Tyvek lets water vapor pass through.  Why would it stop radon gas?

	Larry

> Tyvek lets water vapor pass through.  Why would it stop radon gas?

Because Tyvek is an air infiltration barrier, designed to stop the flow
of air.  Think of it as Gore-Tex for your house.
How big (in size, not atomic weight) are nitrogen, oxygen, water, and radon
molecules?

    	Tyvek = Gore-Tex is a good analogy. Gore-Tex is a breathable, water
    repellent fabric. Air and gasses can pass thru each material. Liquid
    water cannot so easily. Tyvek will have no effect on radon
    accumulation.  - Chris

I thought the purpose of Tyvek was to let water vapor through but not allow
air to pass through?

Anyway, for what it's worth, a radon "molecule" is a single, large, very heavy
atom.  A water molecule is quite small, and nitrogen and oxygen are larger
than water, but not as big as a radon atom.

-Mike

I don't think Tyvek has much to do with radon.  Radon is a problem (if it's
a problem) in tight houses.  You don't *need* Tyvek to make a tight house.

I imagine someone can come up with a statistically correct, numerical value for
how much tighter Tyvek can make a house.  I'd imagine, though, that if radon
would kill you in 80 years in a non-Tyveked house, the same conditions would
kill you in 79.9 years in a Tyvek-ed house.

Nobody asked ...

    
    I think it's unwise to make assumptions regarding radon and Tyvek,
    without actually studying it.  Tyvek is primarily used as a wind
    infiltration vapor.  Yes, air and water vapor can pass through it,
    but they will not "blow" through it.  I suspect that Tyvek *might*
    make a big difference in radon concentration, if the house was not
    already built tight, but I wouldn't want to make any blanket
    assumptions.
    

Appropos to this discussion...

I know that one should not place insulation above recessed light fixtures.
But is it safe and to code to surround the outside of a junction box or
outlet box with insulation?  I assume so, but...

	Thanks,
	Larry

    We are putting on a second floor, and are trying to decide on
    insulation and windows.  Clearly more is better, but to get the
    biggest bang for the buck ...
                             
    Does it pay to put 6 inches in walls and 8 inches in ceiling if
    we are using the standard double-glazed windows (probably Malta
    windows)?  Would we be getting more payback by buying triple glazed
    windows?  And if so, how much are they?  Where do you get them?
    
    (We will also have a glass door to a deck off the second floor.
     Probably French or atrium, because sliders lose more heat)
    
    How should we weight these?
    

    
    	The US Dept. Of Energy  has a "Recommended R-Value" chart which
    is available at various places. ( like Builders Square, Channel, etc.)
    
    	It boils down to:
    
    		Exterior walls - R 11
    
    		Crawlspace walls R 19 (ex. Fla, R 11)
    
    		Floors (over unheate areas) R 19
    
    	For ceilings it doesn't boil down easily. Depending on where you
    live, and your heating system, they suggest from R 49 down to R19.
    
    	Generalizations:
    
    			Area			ELEC		OIL,Gas
    
    		Maine, N. Dakota, NW Montana	49		49
    
    		NE, NY, OH,Iowa,ILL,MICH,
    		North Missouri,S.Dak,Mont,
    		WY,Co,Nev,Utah,Neb		49		38
    
    		Wash, Ore, Id,New Mex,		38		38
    		Pa, W. Va,Tenn,
    
    		Warmer places			38		30
    
    		Really warm places, Tex, S. Ari	30		30
    
    
    	For more information: DOE Insulation Fact Sheet (DOE/CE-0180)
    
    		US DOE
    		Office of Scientific And Technical Information
    		PO Box 62 
    		Oak Ridge
    		TN 37831
    

    Definitely put the insulation in the walls and the ceiling.  Heat rises
    and the insulation in the ceiling will keep the heat in the room.  A
    ceiling fan can be used to help circulate the warm air at the ceiling
    level back down to foot level.

    The insulation in the walls forms a blanket against outside air and
    winds from coming into the house and cooling it off as well as keeping
    the warm air inside.  6 inches in the walls will give you about R-19. 
    The highest windows I have heard of are about R-5.  That makes your
    windows in effect, large holes in your insulation blanket.  What you
    might get by getting more expensive windows is going from an R-3 to an
    R-5.  The difference is significant for _windows_ but in the scheme of
    keeping cold out and warm in, not much when you are talking R-19 for
    your walls and R-30 for your ceiling.

    The insulation should be your number 1 priority and the then getting the
    highest R value windows you can as number 2.  You can always replace, 
    upgrade, or add storm windows at a later date, but to come back and
    add insulation to your walls and ceiling is not easy and is usually
    more expensive than during initial construction.
    

   
    The previous reply about insulation makes sense. The person who
    reactivated this conference also mentioned he might get Malta windows.
    IMHO I would not get them. There the kind of windows general
    contractors get when they are building a house quick and cheap.
    I had a conversation with a builder and we had a good laugh over
    them.
    See the topic on Malta's. Also,if you want energy efficient windows
    you may not want windows with a "tilt" feature.
    
    	Someone who *may* not know what he is taking about.

    		Domenic

    I'm not sure it belongs here, but this is the first discussion of it:
    
    If you do make an 'airtight' house, with all the resources at your
    disposal, then you have problems with Radon and 'sick house' syndrome,
    etc.  Do air-to-air heat exchangers create a positive pressure inside
    your house, or do you need to do something special?
    
    I notice a musty smell that appears to be from the attic whenever we
    have the central A/C and the 2 window A/Cs cranked up for too long,
    which I suspect comes from creating a negative pressure inside the
    house...
    
    Willie

    I have a similar situation.  I put 6 in. of faced fiberglass under
    the porch, then to keep the critters from nesting in the stuff, I put
    up 6 mil plastic and covered that with plywood.  Now a friend tells me
    and I think he is probably correct, that I may get moisture in the
    insulation because the fiberglass can't breath through the
    plastic/plywood covering.  What I'm proposing to do is just take a
    drill (maybe 1/2 in) and perforate the plywood/plastic in a myriad places.
    Will that do it?  I wish now I hadn't put up the plastic, but I didn't
    think my plywood cover was going to be thorough enough to keep out the
    mice.  As it turns out, it's quite tight all by itself and probably
    would have done the job.  
    
    Opinions please.
    					- Vick

I've been meaning to write this note for a while.

One thing NOT - repeat - NOT - to do when insulating a floor, particularly if
the floor is over a crawl space which you cannot enter.  Do NOT put the 
insulation in from the top before the flooring, stapling the facing to the
joists and relying on the adherance of the insulation to the facing to keep the
insulation between the joist.  When you later look under the crawl space, and
find that several strips of insulation have fallen out from between the joists-
leaving the facing behind - and you can't do anything about it, you will be
very frustrated.  Always provide an alternate means of support under the
insulation.

Can you hear the voice of experience?

Paul

What with energy prices going the way they are, I'm thinking about how 
to get better insulation for my old home.  It has blown-in cellulose
insulation, but I don't know if the wall cavities are completely full.
Also, I am planning to re-side the house sooner or later, so I don't 
really care if the existing shingled siding gets messed up or covered up.

Here are the options that I think I have.  I'd appreciate advice about
which to do.

  1)  Tear off the sheathing, discard the cellulose insulation, and put in 
  fiberglass.  This would be costly, make a big mess, and I'm not clear it 
  would gain me that much.

  2)  Drill holes in the sheathing and try to blow in more insulation.
  This should be cheap, especially since I don't mind cosmetic damage.
  Whether it helps depends on whether my cellulose has settled.

  3)  Do 1), but also cover up the shingles with sheet insulation and
  apply new siding over it all.  The most costly option of all, but
  potentially the best results.  

The thing that worries me about #3 is, what about my windows?  Can I
extend the sills out if I make the walls a couple of inches thicker?
Or do I need to replace the windows to add insulation?

Alternately, maybe I should just put in replacement windows and leave it
at that -- perhaps that is where my energy problem really lies.  Can anyone 
suggest means to figure out just where my heat loss is really happening?

	Thanks,
	Larry

re: .8

Have you had an energy audit?  Contact your local gas or electric company.

If you want to splurge on the analysis end, I think there are ways to get
infrared photos of your house taken and analyzed to spot the heat loss.

   Gary

    Re: .8
    
       Our Cape was built in 1968 with an unfinished 2nd floor. The 2nd
    story floor was insulated with blown-in cellulose by the heating
    contractor (electric heat). 
       When we finished the upstairs with 2 bedrooms and a full bath, we
    had to take up some plywood flooring to re-route some plumbing. The
    cellulose insulation, after 30 years, hadn't settled at all. It was
    packed in as firm as the day it was done. 
       I worked for a year installing blown-in insulation. Both the
    cellulose and the 'man-made' wool, supposedly this stuff won't settle
    at all over a period of many, many years.
       But, I agree, get an energy audit before commiting to any major
    overhaul that you are contemplating.
    
       Good luck,
       Dave

    .5:
    
    Do you think that applying "chicken wire" or some other lightweight
    wire screening to the underside of the joists, before the insulation
    and underlayment goes on (i.e., while you can still reach underneath
    the joists) would suffice?
    
    Dick

    .re .6  Chicken wire underside of joists
    
    Refer back to .2  They have the right idea.  You should be able to buy
    piceces of wire sold just for this purpose.  They are about 2/3 the
    thickness of coat hanger wire, straight with pointed ends and come in
    two lengths: 14 1/2 and 22 1/2.  
    
    You stuff your insulation up between your floor joists with the kraft
    paper or vapor barrier facing the heated side, and then wedge the piece
    of wire between the two joists.  Assuming 2x dimensional lumber is used
    for the joists spaced on a standard 16 or 24 inch center, the pre-cut
    wire is just a tad longer than the gap between joists.  The pointed
    ends, really just where they were cut to length sharp, stick into the
    joists and provide a means to keep the insulation up.  Easy to use and
    inexpensive.  Figure one wire about every 2 linear feet of insulation.
    
    I used them when I insulated my floor in my crawl space.  I put down 4
    mil plastic on the dirt floor to reduce moisture in the space and then
    went back and put up the insulation.  Dirty and tiring but I can tell a
    difference in the heating bills and the way the house feels.  Would I
    do it again?  Sure in a heart beat after seeing the results and only 1
    weekend of labor.
    
    In your case I would also suggest that you install some sort of wall
    structure around the perimeter of the porch.  This will help reduce
    wind under the porch which will help to keep the envelope of warm air
    more stable.  The protected area will stablize and actually be warmer
    than the outside air and provide less of a heat sink than if the area
    was open.
    

    Refer to a previous note???  (Well, I do, but when I'm looking for help
    on my own projects...)

re: "...pieces of wire sold just for this purpose.  They are about 2/3 the
thickness of coat hanger wire, straight with pointed ends and come in two
lengths: 14 1/2 and 22 1/2.

Aren't these called 'tiger teeth'?    

    I don't know what the brand name is, but they are generically called
    insulation supports.  They cost about 4 or 5 bucks a box at Grossman's
    and a box will do maybe 150 square feet if you follow the directions.
    That's the kind for 16 inch centers.
    
    					- Vick

>    If you do make an 'airtight' house, with all the resources at your
>    disposal, then you have problems with Radon and 'sick house' syndrome,
>    etc.  Do air-to-air heat exchangers create a positive pressure inside
>    your house, or do you need to do something special?
    
    Most air to air heat exchangers work in one of three ways ... one is
    to have a fan on inlet from outside creating a slight positive pressure
    (bear in mind that the exchanger outlet is as big or bigger than the
    inlet) which should eliminate "sick home" syndrome.  The second is an
    exhaust only fan, which creates a slight negative pressure and the
    potential for sick house.  The third and best is a pair of balanced
    fans both pushing and pulling, leaving a balanced pressure.
    
>    I notice a musty smell that appears to be from the attic whenever we
>    have the central A/C and the 2 window A/Cs cranked up for too long,
>    which I suspect comes from creating a negative pressure inside the
>    house...
    
    In fact this occurs because of moisture condensing on the exterior
    (attic) side of your walls or ceiling ... Vapour / moisture barriers
    always go on the warm side of insulation ... well, in our temperate
    climates, the warm side in the summer is the OUTSIDE which makes a
    mockery of the building code ... however, the general idea is that
    we generally cool less than we heat and the heating season produces
    a greater thermal gradient, so we worry more about that.
    
    The only way to cure this problem is to NOT cool your house so much in
    the summer, or replace all your insulation with a foam insulation.
    
    

    .re -1
    
    You may heat more than you cool and the difference where you live may
    be larger in the heating seasion than in the cooling season but that is
    not true throughout the country. 
    
    Here in Atlanta in regularly stays in the high 90's *in the shade* for
    months on end.  The heating season here is equal to the cooling season
    in length and the difference in trying to heat the interior space to a
    comfortable temp vs. the outside temp actually is a smaller margin in
    most cases than trying to cool the inside temp vs. the outside temp.
    during the cooling season.  
    
    Not everyone lives in the great frozen north ;^)
    
    Insulation and vapor barriers play an important role in keeping the
    heat and high summer hummity outside in the south.

    Of course it is true that there are people around these conferences
    who are not in the great white north! :-)
    
    So, my discourse was essentially incomplete ...   What I was trying
    to imply was that many older homes in the northern and semi northern
    climes were built thinking more of winter than summer, and with
    very little thought to cooling in the summer, so you tend to get
    a lot of problems like this with poor insulation / vapour barrier
    combinations.
    
    Stuart

    I would be more inclined to believe the musty smell is coming from
    insufficent insulation, and an incomplete vapor barrier. Insulation
    works equally well in preventing transfer of cool in summer, and warm
    in winter. It sounds like you are getting a dew point situation instead
    of holding the cool air within the house. An air to air exchanger
    could reduce the smell through ventilation, but it would not solve the
    real problem.
    

I've been seeing ads recently for "premium" fiberglass insulation that has
somewhat higher R-values than the standard stuff.  For example, the 3-1/2
inch batts are rated R-13 rather than R-11.  How do they do this?  Doesn't
making the fiberglass more dense actually reduce the insulation level?

				Steve

    Maybe they give you *less*?
    
    Edd

    Possibly it's just more uniform in density, so its overall insulating
    effectiveness is greater.

re: .13 

>                                                              ...  Doesn't
>making the fiberglass more dense actually reduce the insulation level?

      I *think* the answer is something like this.  
      
      At  a very low density you have poor insulating value.  As you add
      density the insulating value increases.  So dose the cost. At some
      point  you  reach  the  best cost/benefit ratio.  This is probably
      around R11 for 3-1/2" batts.  Now you can increase the  density  a
      bit  more and still increase the insulation value, up to, I guess,
      about R13, but the cost/benefit increases -- i.e. the dollars  per
      each unit of R value increases.
      
      So, for most applications R11 is more cost effective.  But suppose
      you have to have R19? Well, the traditional method is to build the
      wall with 2x6s.  But it just might be cheaper to use 2x4s with the
      R13 insulation, plus 1/2" ridgid insulation  to  add  R5.   Add  R
      values  of  1/2 for the exterior sheathing and interior sheet rock
      and you've got a [maybe] cheaper R19.  (In fact, it might even  be
      better  since  that  1/2"  ridgid  insulation isn't interrupted by
      studs, like the 5-1/2 batts would be.)

      Any other theories?

>      At  a very low density you have poor insulating value.  As you add
>      density the insulating value increases.

Actually the fiberglass in fiberglass insulation isn't a very good insulator.
It is the _air_ in the insulation that is the insulator.  The fiberglass
is there to prevent convection currents, which is what ruins the insulating
properties of empty walls.

If you think denser fiberglass would make better insulation, take this to
the limit - 3 1/2" plates of solid glass in the walls.  Would that be a
great insulator?  No!

re .13:  To make a better insulator out of 3 1/2" of fiberglass, I can guess
at a couple possibilities:  The air cavities are smaller (less convection),
the fibers are shorter/thinner/more twisted so there are fewer conductive
pathways for heat (fewer fibers reaching from inside to outside, conducting
heat along their length), or maybe simply less density.

-Mike

    FWIW, from a table of R values per inch thickness:
    
    Glass Wool
    	batts and blankets	3.1
    	loose-fill		2.3
    	high-density		4.2
    
    Glass			0.15
    
    -al

It's been noted elsewhere in this file that 5.5" fiberglass insulation,
compressed into a 3.5" space, provides slightly more insulation than
ordinary 3.5" fiberglass.  HOWEVER, it provides *less* insulation than
putting that 5.5" fiberglass into a 5.5" space.  It can also lead to
nail pops, but that's another story.

It would be interesting to compare prices (at the same place at the same
time) for ordinary and higher density fiberglass insulation.  One assumes
that the ordinary kind is more cost effective, if one has the space for it.

	Enjoy,
	Larry

Re: .19

The high-density stuff (I presume that's what the Premium is) is more
expensive per square foot than the regular stuff.

			Steve

Actually, I was thinking of price per square foot divided by R value.
One can fairly easily find charts of insulating value per inch, but
I've never seen a chart comparing cost per R value for the various
types of insulation.  Such a chart would have to be interpreted
intelligently, of course (e.g. total cost for fiberglass should be
adjusted for extra construction cost if the studwall must be thicker)
but it wood be useful nonetheless.  

	Enjoy,
	Larry

A follow-up to .30, where I describe a house that had blown-in insulation
installed through the perfectly decent-looking shingles.  They put up new
*wooden* clapboards this year.  Looks really nice, particularly compared
to the tacky vinyl that's taking over the neighborhood.

I have a question about insulating my attic.  I tried to find the answer in the
index, but there was so much information lumped into one note, that I felt my
specific question warranted a note of it's own.

I have an old house (built in 1901).  This house has a hip-roof.  This is the
kind of roof that has 4 sides joining at the top.  It is great, because the
attic is a good size and can be used later.  My problem is that there is no
insulation in the attic at all.  What I want to do is insulate the ceiling,
so that the room could be finished off later.

I understand that I will want to put in the propa-vents for the whole length
of the ceiling.  This ceiling goes all the way out the the walls.  I can see
daylight if I lie down on the floor and get to the edge.  I would like to put
the insulation over the propa-vents.  What I am not sure of, is what kind of
vapor barrier would be best.  I priced insulation at Builder's Square and saw
75sq ft. of faced R-19 at about $18.45.  I also saw what looked like 75 sq ft.
of R-19 unfaced for about $10 or $11.  My thought was to get the cheaper
unfaced insulation, and cover it with a plastic sheating.  I thought this would
be a sufficient vapor barrier, and eventually, it will be covered with sheet
rock, or whatever.

Also, my roof has slate shingles.

I read where the roof is where something like 70% of the heat loss occurs.  In
my case, where I have no insulation in the roof area at all, I would think I
could save quite a bit on my heating bill.

Ed..

I changed the title to more accurately reflect your question.  Actually, I 
think that the unfaced insulation and plastic makes a BETTER vapor barrier than
the faced insulation, because there are so many fewer seams.

You're going to have another problem, though, which probably deserves a new, 
appropriately titled note of its own.  Simply using propa-vents isn't going to
do anything for you.  The point of them is to allow air flow from the soffit to
the ridge vent that you install when you insulate the attic on a normal roof.
But with a hip roof, the majority of the rafter bays don't ever make it to a 
ridge, they butt up to the hip rafters.  If you want to insulate and close up 
those bays, you're going to have to figure out a way for the air to ventilate 
out of the tops of them.

Paul

Owens-Corning Fiberglass has a very informative booklet that is available
free at many retailers - I picked one up at Somerville Lumber.  It tells
you when to use and when not to use a vapor barrier.

When insulating an attic, the vapor barrier should be towards the "warm in
winter" side, which means UNDER the insulation in the attic floor.  This is
trickier to do with plastic than it is with faced insulation.

You'll want better than R-19 in the attic floor if you can fit it.  R-25
or R-38 would be much better.

			Steve

I just had my addition insulated by Moore Insulation.  It has a cathedral 
ceiling.  The vapor barrier would have been plastic.  However, Carl Moore 
suggested that I put a layer of 1" rigid insulation under the 9" batts.  That 
way, I would have the equivelant R value of my existing attic (12").  It cost
me an extra $250 for 10 sheets of the stuff. They also taped all the seams.

btw. I found that it wasn't worth it for me to do the insulation myself. It
cost me $150-$200 more to have it done - and it was done in 6 hours - and I'm
not scratching!!

btw2. You may find that you have to do something like the above if you want to
convert your attic to living space, as you'll have to do things to the current
building codes.  I believe the code specifies whatever R value (38?) 9" of 
fiberglass insulation gives you.  If your rafters aren't 2x10 (my existing 
structure is 2x6, for example), you can't use 9" of fiberglass without 
compressing it.

Re .2 my plan is not to put the insulation in the floor.  I am trying to make
attic useable for more than just storage.  To do this, I am having to put the 
insulation in the attic ceiling.

Paul - I had not considered any difficulty with putting the propa-vents in.  I
will start a new note to discuss this item.

The construction is with older 2x8s, I believe.  I will check.  If so, then I
should be able to fit 9" with no problem.

Ed..

    If you insulate the roof but not the floor, you will still be heating
    your attic.  You will save the heat from going out through the roof,
    but you will still have a warm attic.
    
    I must admit, I can't picture it in a hip roof.
    
    Elaine
    

    I misunderstood the original question.  You DON'T want to insulate
    the attic ceiling unless you have finished it and are heating it.
    There's no point to it and you run the risk of ice buildup on the
    roof.
    
    		Steve

>>The construction is with older 2x8s, I believe.  I will check.  If so, then I
>>should be able to fit 9" with no problem.

Which means ther're probably 8" wide, right?  Even so, don't compress the
insulation.  It reduces its R factor.

    And if you then add the propa-vent, you'll further compress the
    insulation. Maybe you should consider using 6" fiberglas insulation.

I agree that I would be heating the attic, but in a way, that is what I want. 
As I had mentioned earlier, I plan to use that space eventually.  So, any
solution that I come up with I want to be sure will fit my future needs.

Also, the floor in the attic is covered by wood planks.  This covers the wiring
to the second floor rooms.  I don't really want to pull up the planks.

So, back to my original problem...

Ed..

So, am I correct in understanding that the R-19 might not be the stuff I want?
What would I rather use?  R-11 (which I think is regular wall insulation)?  Or
is there another that I should use?

Ed..

For about the hundredth time....  :-)

A given batt of insulation will decrease in R value if it is compressed.  
However a given space will have a higher R value if a batt is compressed into
it than if a batt simply fills it.  The thicker insulation more completely 
fills in all the space in the wall cavity.

For example, take a 6" space.  You could put in 6" batts, which are about
R19.  Or you could stuff in 9" batts,  which are about R28 if allowed to expand
fully to 9".  Stuffed into 6", they won't give you R28 any more, but they will
give you a little more than the R19 that the 6" batts would - perhaps R21 or 
so.  Usually it's not worth the extra cost - a 50% cost increase for a 10%
insulation increase.

However, given that you have a 7-8" space, it may be worth it.  The 6" batts
won't fill the space completely, and the 9" batts won't compress as much.  I'd
guess that you'd get R25 or so out of the 9" batts.

Actually, as I think of it, if you were to use 6" insulation, you probably
wouldn't need propa vents for most of the area - an air space would exist
above the insulation naturally.

Paul

re .9:

You're probably right in wanting to insulate the roof rather than the attic
floor (assuming that you really do get around to finishing the attic).

When we bought our house, the roof was insulated.  Since the attic is
unusable as living space (except by munchkins), we decided to insulate
the attic floor and properly ventilate the attic.  Our attic floor is
also covered by planks, so we had cellulose blown in.

re .11

>>Actually, as I think of it, if you were to use 6" insulation, you probably
><wouldn't need propa vents for most of the area - an air space would exist
>>above the insulation naturally.

That's definitely correct.  However, if you get a permit and thus have
inspections, the inspector may require them anyway.  Also, as I mentioned in an
earlier note, the code requirement for the insulation is probably R-30. Six
inches at R-19, or six inch batts with one inch rigid (R-8, I think), would
not bring you up to code.

Of course, if you bypass the permit process...

    I am also insulating my attic.  I have only seen R-19 or R-11 faced 
    insulation.  Where has anyone seen R-28 9" faced insulation available ?
    Anywhere that I have been, anything over R-19 is unfaced. I live in
    the southern NH, northeast MA area. Any help would be appreciated.
    
    Dave
    

    You can buy faced r-30 9" bats from Grossmans, Summerville Lumber
    and probably other places. 

    I've bought the 9" faced at both places. Manchester,Bedford stores 
    respectively.

    George

If you are required (or wish) to put in more insulation than you can fit
between your rafters, how about using 6" fiberglass, and then facing it
with foam sheet insulation?  I think you can then attach the sheetrock
directly onto the foam (using long screws, of course).  That method will
let you get any level of insulation you want, without requiring you to
build a second ceiling to allow thicker fiberglass insulation.  

One advantage, I would think, of the faced fiberglass is that you can
attach it more securely.  I'm not sure how you'd keep unfaced lengths
from buckling.  If you do put in propavents, that's not a problem, but
if you do not, then you must do something to make sure that the 
insulation does not touch the roof and cut of the ventilation.

	Enjoy,
	Larry

As I mentioned in .3, I did add 1" of rigid under the batts on my cathedral. 
The following caveat is probably not applicable in your case, but could be for
anyone adding on to an existing structure.  I did not account for the extra 1"
of insulation when framing.  Now that the ceiling is plastered, I have a 1"
overhang (underhang?) where the cathedral ceiling meets the existing, flat 
ceiling.  Fortunately, I will have a cabinet there to hide it.  Thus, make 
sure you account for that in any plans.

I read a brief article in some magazine over the weekend about a high density
insulation that is made to get a higher R value in a given space.  It is 
supposed to be better than packing regular insulation into a smaller than meant
for space.

    Has anyone heard of, or used "BIB" insulation? BIB stands for Blow
    In Blanket, and is told to be 25-50% better (in terms of R-value)
    than conventional batts. The product claims to be non-settling,
    and does not form pockets which can greatly reduce the R-value.
    Cost is about 25% higher than conventional.
    
    Thanks,
    John

I have a question about insulating the basement ceiling...

I believe the instructions on the insulation say to put the insulation up
with the faced side up (so the exposed fiberglass is faced down).  Why is
this so?  This is for an unfinished basement.

Thanks,
B.

    The faced side (the vapor barrier) should be toward the heated space.
    In this case, it's the basement ceiling.
    The idea is, you don't want water vapor in the heated space to migrate
    through the insulation and condense on the vapor barrier inside the
    insulation.  If the vapor barrier is on the "cold" side of the
    insulation, the situation would be set up for that to occur.
    
    

    Also check out notes 84, 85, 268, 1597, 1854 and 1111.11 for more tips
    on basement insulation.

RE: .12

The reason for my asking about the insulation is that we just went through
insulating part of the attic and  itched for a while.  We didn't really want
to leave the fiberglass exposed to the basement area because of the potential
for all that fiberglass to get loose.

Would putting up another vapor barrier on the bottom side be okay?

Thanks,
B.

    
    Probably wouldn't hurt, but you may want to consider something like
    Tyvek instead; stronger, and vapor-permeable.
    

    re:.14
    
    You don't want to put another vapor barrier lest you create a micro
    climate inside your floor joist bays...  something water permeable
    would'nt be a bad idea however... tyvek comes to mind...
    
    Fra
    

    I read in here somewhere that after a couple of days, all the loose
    fibers should have fallen out.  Our cellar ceiling is insulated with
    the barrier side up and we've never had a problem.
    
    Chris D.

    OK, this all sounds good.  One more question.  I'm doing my porch floor
    also, very similar to the base noter.  I've got 2x8 joists and access
    from above.  I plan to put in some polyisono-whatever it's called
    (R-maxx, etc) sheets under the joists, chicken wire underneath them,
    fiberglass bats between the joists, and a vapor barrier above.
    
    But -- what about ventilation?  Will the cracks between the solid
    sheets be enough?  I could drill 1" holes in the header board and put
    in button vents, but won't the vinyl siding ruin their effectiveness?
    Do most houses side over the header board, or just leave it exposed to
    the weather?
    
    Furthermore, the simplest way to vent the 2x6 wall cavities seems to be
    drilling a 1" hole in the sole plate for inlet, and a 1" hole in the
    top plate for outlet.  But now since the floor-insulation space is
    providing ventilation for the walls as well, the problem only gets
    worse...
    
    Any thoughts on my best option? (by the way, it's a pier/platform
    foundation, built on sonar tubes, with the header sitting on the sonar
    tubes (no mudsill).
    
    -Joel

    I am going through a similar insulation project now.
    
    I have fiberglass under the porch...which is over a crawl space.  I 
    used a material called "typar"(like "tyvek") to cover the insulation.
    Note: I used the wires too,to hold the insulation in place.
    
    I secured the typar first with staples,then used 1x3s spaced every two
    feet,nailed to the bottom of the joist to additionally secure the
    "typar" from the wind.
    
    The "typar" will breathe somewhat,so that you will not have a vapor
    barrier..BUT it will keep out the mice/bees/wind.
    
    The idea was not mine....the building inspecter suggested it.
    
    Marc H.

    re:.11
    
    why do you feel you need ventilation...???  theres no need to drill
    whatsoever... unless you vapor barriered both sides of the insulation.
    
    am I missing something...
    
    Fra

>    The "typar" will breathe somewhat,so that you will not have a vapor
>    barrier..BUT it will keep out the mice/bees/wind.
    
      Typar, Tyvek and similar products will *NOT* keep out mice.  And I
      would not be surprised if it failed to keep out bees.

    Re: .14
    
    I can understand the mice(munce through anything)...but why the bees?
    
    Marc H.

    Instead of the chicken wire, which does nothing more than hold the
    insulation up in the bays, you might consider the more expensive
    screened wire... (use it for cages, screening loam etc...) which will
    work nicely at keeping out mice and other small rodents.  won't do
    anything for bees, but the tyvec over it, tacked up with a wooden frame  
    around the perimeter should work nicely for most varietys of conventional 
    bees.
    
    Fra

    > Instead of the chicken wire, which does nothing more than hold the
    > insulation up in the bays, you might consider the more expensive
    > screened wire
    
     Sounds like an excellent suggestion.  I will.
    
    It sounds surprising that the Typar/vec would provide enough
    ventilation... I don't think I was clear enough about the main point.
    
    It seems to me that:
    Warm moisture from the room can enter the walls (no vapor barrier is
    perfect).  Thus the need for wall ventilation.  If the wall ventilation
    inlet is from holes drilled through the sole plate into the floor
    insulation space, then this translates into a need for floor
    ventilation (I suppose that, since warm air travels up, floors wouldn't
    normally need have condensation, and hence wouldn't normally need
    ventilation, but in this case it seems like they would... right?).
    Unless I'm missing the point, and there's no need, for some reason, to
    ventilate walls/floors.  But I have heard that badly ventilated walls
    are a strong cause of peeling paint.
    
    So -- how do people provide this ventilation?  For 200 s.f. of floor
    and 320 s.f. of walls, this means 520/300 = 2 square feet of
    ventilation.  Does porosity in the Typar/vec provide this much inlet
    space?

    there is no need to provide any ventilation in the floor or the bays of
    the wall... any moisture will naturally rise into the ceiling and this
    will exit the house via gable vents or ridge vent.  With 2x4
    construction people use 3 1/2" faced/unfaced insulation... where are
    you planning to provide ventilation if the bays are full of insulation?
    not that you need to anyway!
    
    I think your over-engineering your project a little.  Tyvec is an air
    infiltration barrier, not a moisture barrier.  Insulation works by
    creating a dead air space...  ventilating will ruin this effect.
    
    Fra

    I am in the process of putting up some insulation on some exteria walls
    in a kitchen that I am remodeling, I am using kraft faced paper and was
    going to put poly over that but I have got mixed answers from people
    that I taalked to. Some people said that because I am plastering I
    should not use both poly and kraft faced insulation because moister
    will build up between them, others said that I should use both. Any
    comments on what I should do??
    
    Thanks 
    
    Tom

    I would only use the kraft paper.  Why add extra work?
    
    If you like the plastic better,then use un-faced insulation.
    
    Marc H.

I've done this, and it works fine.  I prefer poly as it cuts down on
air infiltration.  Some people will tell you to slash the kraft paper before
applying the poly, but if the poly is right up tight against the paper,
it's not necessary.  Of course, unfaced is preferable, but it's harder to
get in some sizes.

However, if there's any sort of an air gap between the two, use unfaced or
slash the paper.

				Steve

    I have already put the kraft faced insulation up and the reason I am
    considering using the poly as well is that alot of the studs were not
    16" so I had to cut most of the insulation to fit which means that it
    is only stapled on one side. Knowing this should I slash the kraft
    paper and put up poly, just put up poly, or leave it as is??
    
    Thanks again
    
    Tom

That was my situation as well.  Given that I was using R-13 batts in a
2x4 cavity, thus resulting in some compression of the batts, I felt it
safe to just put the poly directly over the paper.  If you feel that
air pockets might form between the paper and the poly, slash the paper.

		Steve

    Remember what the purpose of the poly is - to act as a vapor barrier.
    You want to prevent the warm, moist air inside a room from coming in
    contact with the cooler insulation and thus preventing condensation
    which runs its insulating properties.
    
    Kraft-faced insulation is supposed to provide a vapor barrier with one
    step.  The paper is coated with tar on the side next to the insulation.
    I think it makes absolutely NO difference what you put on the living
    space side of the kraft paper to make it more effective.  There is no
    way condensation can occur between the poly and kraft if the poly is
    working.  There is no way condensation can occur if the poly is not (a
    rather unlikely event) as the temperature/humidity on one side would be
    identical to the other (the definition of "not working").
    
    You will have a problem if your walls are cold and your inside air is
    warm and moist.  This, of course, is the entire reason you insulate in
    the first place...
    
    Bottom line - don't worry about it, in fact, do it. Slashing the kraft 
    paper is a waste of time.  I've seen many professionally done jobs
    where poly was laid over faced insulation.
    
    Al
    

For a layman, I understand that the higher the R-factor number on the
insulator, the better it will insulate.

I'm am trying to figure out the law of diminishing returns on R-factor.
How much is enough and how much will too little cost.

I know I have asked a lot, but if any of you have schooling in this,
can you educate us layman to help us be better judges of insulation?


As another example, 360 BTU/square foot loss in heating
translates to what in approximate cost or electrical usage?

    Re: .20
    
    Some basics--
    
    3413 BTU/hour = 1000 watts
    
    1 gallon of heating oil contains about 140,000 BTU's. A typical
    running efficiency for an oil fired burner is in the range
    of 80-85%.
    
    I believe that gas is measured by therm's where each therm
    contains 100,000 BTU's. Incidently, some time ago I checked
    the price of propane and at that time it cost $1.15-$1.20/therm.
    
    Note that oil can be purchased for under a $1.00/gallon and it
    has significantly higher energy units per gallon than 1 therm of
    propane. The message is that oil will cost less as a fuel than
    either gas or electric fuel.
    
    You should now be able to calculate costs for known BTU/square foot
    heating losses.
    
    Joe

    Re: .21
    
    The efficiency number quoted for oil burners in often the efficiency
    of burning the oil.....not the efficiency of converting oil to hot
    water.
    
    Marc H.

    Re:.22
                         
    The efficiency numbers that I gave in reply .21 were related
    to the energy conversion from oil to water minus some losses
    related to radiation and conduction from the fire box. Oil will
    burn with efficiencies approaching 98-99% even when the fire 
    operates with poor air and fuel mixtures.
    
    
    The problems associated with efficiency in boilers or furnaces
    for that matter, are usually governed by other factors. Some of 
    the major ones are:
    
    		* Temperature difference between the exhaust gases
    		  and the water jacket. The temperature difference
    		  should be as large as possible, ie- low water
    		  temperature in the boiler. To take advantage of this,
    		  one needs more radiation than is ordinarily found
    		  in homes built by contractors.
    
    		* Clean surfaces on the heat exchanger. Carbon is 
    		  an excellent insulator. If I recall correctly, R of
    		  1/8 inch of carbon is equal to 1 inch of fiberglass.
    		  
    		* Flow rate of the gasses through the heat exchanger.
                         
    		  This is why operating a burner with too much air
    		  will result in lower efficiency. Operating with
     		  not enough air will give high efficiency but only
    		  until the smoke from poor combustion causes a
    		  carbon built up on the heat exchanger.
    	
    I made mention in an earlier note about a study done at Brookhaven
    National Institute about boilers. This topic is explained well 
    in their report. There is also a booklet published by Beckett, the
    burner people, on how to adjust a burner. The booklet costs about
    $3-5.00 and would be worth purchasing if its still published. Beckett's
    book is very good at explaining the fundamentals.
    
    Joe	  
    		 
    

There are two main factors that determine when you have too much insulation.

First, you have too much insulation if you have too much air infiltration.
I have a book at home that quantifies this, but the quick summary is that
when you are building, it pays to be *very* careful about infiltration.
E.g., use plastic between the drywall and the studs, use those foam inserts
in outlet boxes on the exterior walls, caulk carefully around windows, etc.

Second, you have too much insulation if you have too many gaps where there
is little or no insulation.  A wall with R100 insulation between the studs
(if there were such a thing) has an effective R value of about 30, because
of the much lower R value of the wood studs.  Most houses have little or
no insulation at the band joists and other such places, which dramatically
reduces the effectiveness of the rest of the insulation.  So the message
is that it is far more important to insulate reasonably well all over than
to insulate some parts of the house really well.  Incidentally, this is
why attic blanket insulation is a good idea, since it lays on top of the
joists and has no low-R gaps between.  However, attic insulation that is
much more than 2x the wall insulation doesn't have a big payback -- if
you could have R100 attic insulation but only R11 wall and floor
insulation, the effective value would be something like R13.  Covering the
entire outside of your house with foam insulation while re-siding may not
work out to be cost effective on paper, but the fact that it doubles
or better the R value where the studs are may well make it pay for itself.

A final comment.  I estimated recently that electric heat would cost me
about 5x my oil heat, per btu.  If you have electric heat, you can get
pretty extreme with your insulation and still have a reasonable payback.

	Enjoy,
	Larry

    Re: .23
    
    Have a source for the Brookhaven Report?
    
    Marc H.

What's a typical R value for a 2x4 or 2x6 stud?

-Mike

    Here's the R value per inch:
    
    Wood clapboards or shingles		1.00
    Stucco				0.20
    Plywood				1.25
    Fiberboard				2.10-2.80
    Hardboard				0.70
    Softwood				1.25
    Hardwood				0.90
    Gypsum Board			0.90
    
    [source: The Complete Book of Insulating]
    
    -al

Sorry for the convoluted form of my reply.  The original question was "how
much insulation is too much", and what I was trying to say was that if you
have lots of air infiltration, adding tons of insulation isn't going to 
help much -- first focus on fixing the air infiltration, then add insulation.  


>Second, you have too much insulation if you have too many gaps where there
>is little or no insulation.  A wall with R100 insulation between the studs
>(if there were such a thing) has an effective R value of about 30, because
>of the much lower R value of the wood studs.  
      
      This  is just not so!  The overall R value of an insulated wall is
      the weighted average of the R values of the various wall sections.
      (Weighted by area of each.)
      
Consider a wall that is half R1 and half R100 -- it *doesn't* have an
total insulation value of R50.  Or for a more extreme case, consider a
house that has two walls at R100 and two walls missing (R0).  The real R
value of this house is R0, not R50.

Here's how to weight and combine multiple R values: 

	(Area1 / R1) + (Area2 / R2) = Area / R

It's the same way that resistances are calculated, except that with
resistors, one doesn't need to factor in the area covered.  And this
is why areas of low insulation value have such a large effect on the 
effective insulation value of an otherwise well insulated wall.

	Enjoy,
	Larry

    
    Say, not to side track to much here, but i'm going to add more
    insulation overhead.  Theres ~3" now and I'd like to add atleast
    another 6 or so inches and hope to be close to R30.  10"=R30 ???
    
    Now the good part.  I have a very lowwwwwww pitch and the only 
    way is to blow it in.  But I dont want to use the cellulose.
    I've seen the fiberglass blown in, but dont remember where!
    
    So......1.  Is FG better than cellulose?  R factor/inch
    	    2.  Where would I be able to get this?
    
    Thanks
    JD

RE: .30

My house has blown in fiberglass.  Working in the attic space isn't much
fun.  As I recall, the insulation certificate says something like 5" for R15
so R3 per inch sounds right.

Re: .28, .29

.29 has the arithmetic correct.  Thus, for the example in .28:

25/6 + 15/6.875 + 60/19 = 100/X;   X = 10.52

If you put R100 in the walls, the average would be 14.39.  If you put
R<infinite> in the walls, the average would be 15.75.  In fact, for this
scenario, R19 looks like a reasonable amount of insulation.

	-JJ

>Here's how to weight and combine multiple R values: 
>
>	(Area1 / R1) + (Area2 / R2) = Area / R

      You're correct that my simple weighted average is wrong.  I should
      know better!

    
    RE:JJ
    
    Ok, were getting close.  Now that I know someone has FG blowin...
    Where did you get it, (dealer or lumber yard) and does it
    cost more or less than the cellulose?
    
    And for the $64 question......  Seeing I have 1/2" sheetrock hanging
    from a 2x4 trus roof,24"on ctn.  Is the FG lighter then the cellulose?
    
    JD

Re: .34

I bought the house when it was 19 years old, so I couldn't say where the
blown in fiberglass came from.

My house also has 1/2" sheetrock hanging from a 2x4 truss roof on 24"
centers, and I haven't had any problems with weight.  The fiberglass that
I've had to shovel out of the way for various projects (bathroom fan, etc.)
has felt to be very lightweight.  It just scratches like hell when you get
it on your skin, worse than fiberglass batts.

	-JJ

    I'd like to insulate a woprkshop that's attached to my house, and have
    no idea what's best to use.  It's the original section of the house
    (built in 16 something-or-other) and is non-standard post and beam
    construction.  Right now there is no insulation at all.  There is a
    ceiling that's been added recently (not insulated) that consists of
    pine planks resting on variously-spaced 2X6's.  There is pegboard on
    the walls, which I intend to rip off.  ON one wall, however, there is a
    set of build-in cubbyholes that I don't want to remove.  This is not an
    outside wall - the garage is on the other side of it.  So I'd like to
    insulate the garage side of the wall.
    
    Would styrofoam be a good choice?  I'm guessing it might be the easiest
    way to insulate all the irregular areas in the wall.
    
    -ellie

    Yes, the joys of insulating an old house!  The roof rafters in one
    part of my house are approximately (sometimes *very* approximately)
    3' apart; the wall studs are more or less on 30" centers, etc.
    
    I'd recommend unfaced fiberglass with a poly vapor barrier over it,
    if only because it's so much cheaper than foam.  You can get fiberglass
    in widths for 16" and 24" stud spacing (so it's actually about 15.25"
    and 23.25" wide), and various combinations of those two widths, plus
    cut-off strips, can be put together to fill random spacings.  I don't
    think it would be any easier to trim foam to fit.  For one thing, I'd 
    just about guarantee that nothing is straight or parallel, and trying 
    to trim foam to conform to warped studs and joists is pretty difficult.
    The fiberglass is much more forgiving in that regard.
    
    For what it's worth, if you need a lot of fiberglass of a given width,
    you can take an unopened roll and saw down through it with a handsaw.
    I did that with a 24" wide roll (23.25") to get two strips roughly
    11+" wide, which worked well for my 12" floor joist spacing.

    BOy, I hadn't thought about the non-squareness of tha place.  Yeah, the
    fiberglass would probably be a lot easier.  I'm sure that if I tried
    cutting the foam to match the odd shapes between the beams, I'd end up
    with "holes".  
    
    thanks,
    ellie

You might want to use cellulose.  It is about half the price of fiberglass,
will fill in any shape space, and doesn't require taking the existing wall
down (you just need some 1" holes).  It also works well in ceilings.  Some 
places that sell the stuff (like HQ) will loan you a blower for free.  

For  the walls that are currently open, fiberglass will be a lot easier to 
install -- *if* you can size the fiberglass to match your spaces exacctly.
Don't leave any air gaps between fiberglass pieces, or you'll lose a lot
of the effectiveness of the insulation.

	Enjoy,
	Larry

There is a new method of insulating new construction on the market. (Well
new to me anyway. Its a method to install cellulose in wall cavities, BEFORE
blueboard and plaster are applied. The cellulose is held in place by an 
    adhesive, applied with the cellulose. 
    Its called Wet Spray Cellulose and is Marketed under "Mr. Insulate."

I am looking for someone who has experience with the stuff and
can tell me, and others, if you would use it again over fiberglass.

ADVANTAGES (per marketing brochure)

More R Value that fiberglass per inch. 
2*4 Walls are R-13 vs R-11 for fiberglass.

Supposedly fills all cracks and prevents air infiltration.

Better Sound deadener than fiberglass.

DISADVANTAGES:
Somewhat more expensive, about $200 or 15%, in a 2,400 square foot house.
                                   
Based on the sales literature, one would chose this method in a minute.
But its the actual performance that would convince me.

Any comments are appreciated

Check the current issue of Popular Science, which talks about the house
they constructed using "new technology" materials.  The insulation you
mention is one of them.

				Steve

FYI, the wet spray cellulose looks like it's the same R value as dry
cellolose, which I think is also slightly higher than fiberglass.
However, the dry stuff is significantly cheaper than fiberglass --
from 2/3 to 1/2 the price of R-11 faced fiberglass in the surveys
I've done.  (I couldn't find any R-11 unfaced fiberglass).  The
wet stuff is presumably better at stopping infiltration than the
dry stuff, although that's probably not a big issue if the house has
an air barrier (tyvek etc) applied to the outside and a vapor barrier
on the inside.

One thing I'm considering trying is to blow in the cellulose after I
staple up a plastic sheet on the wall but before I put up the wallboard.
If this works, it ought to be about as convenient as the wet stuff, but
a lot less expensive. 

	Enjoy,
	Larry

    They did the 'house of the future' on Hometime with that kind of
    insulation.
    
    That set of shows may be repeated in your area, or you can always buy
    the tapes (their main business).
    
    	-Barry_who_watches_both_TOH_and_Hometime-
    

    An additional advantage you'll get with the wet is the resistance to
    compression and settling. The dry stuff doesn't stick to anything,
    so you wind up either putting too much in, which drops your R value,
    or putting enough in, but having it settle over time.
    The wet stuff can be sprayed on the bare studs at the proper
    thickness, and is designed to stay in place afterwards. You can
    get into nooks and crannys better without plastic up also.
    I don't know how they compare price-wise, however. Last I heard
    (on Homtime?) was about 20% higher than fiberglass installed.
    
    John

    
    
    I guess i may have been ripped of then....
    
    
    While my house was being built I convinced the builder to let me
    upgrade insulation from fiberglass to blown wet cellulose in the
    walls and an increase to r35 in the form of blown rock wool in
    the attic at a cost of $750.00
    
    
    Ben,
    

Sounds like a lot of extra attic insulation for just $750.
And although uninstalled cellulose costs less than fiberglass,
it costs more if you have to pay for installation.

    Can anyone tell me that advantages of fiberglass insulation over blown
    in insulation (assuming a proper vapor barrier.)
    
    I am in the process of renovating a cabin and have some of the walls
    down to the studs. It would be easy to install fiberglass at this
    point, but having recently blown in insulation in another part of the
    structure, I know that I can do it again for much lower cost. No only
    that but doing blown in insulation is really *easy*! 
    
    	What are the real advantages of fiberglass over blown-in celulose?
                      

Blown-in cellulose has a slightly higher R-value than fiberglass and is
just as fireproof (it's heavily dosed with borax).  Disadvantages: it's
messy when you have to work in the walls, and there's usually no vapor
barrier.

Blown-in is typically used when walls are to be left intact.  When we had
insulation blown in, the installers removed shingles, cut holes in the
sheathing, blew in the insulation, covered the holes, and reinstalled the
shingles.  Since there were lots of wall cavities (bounded on the sides
by studs, on the top and bottom by firestops), it was a lot of work.

If you find blown-in easy, then do it.

    How well does it withstand gravity, when in tall and narrow cavities
    between wall studs?
    
    Dick

    re.37
    ....real advantages.....
        Celulose dosen't itch.
    
    -j

    re. 40
    ....real advantages.....
        Celulose doesn't itch.
    
	    Sure it does.  It may not be 'as bad' as fiberglass but it
	still irritates your skin.  Even worse, it gets up your nose 
	sumthin' fierce!

					Tim

    And if you are sensitive to the fire retardant they use in cellulose
    then you *really* itch.  Some people really react to borax ... in
    spite of 20 mule team diapers!
    
    Stuart

I really don't understand why anyone would use blown fiberglass.  Most of 
us can blow cellulose with just a dust mask (I used my $20 asbestos mask
because I had it handy and it sealed around my face better).  Everyone has
got to wear a full kit of protective clothing to blow fiberglass.

Blown fiberglass has some disadvantages compared to cellulose.  First, it
can be overblown if you aren't careful.  If you (or an unscrupulous
installer) set the blower too high, it fluffs up too much and doesn't give
as good an R value.  I'm told cellulose doesn't have that problem.  Also,
convective currents in the fiberglass can dramatically lower the R value 
when the temperature drops to a certain point (I think 15 degrees F).
Again, that doesn't happen with cellulose.

	Enjoy,
	Larry

PS -- I bet within 10 years, someone will demonstrate a link between 
breathing fiberglass fibers and lunch cancer...

re .43:

I think the question was blown-in cellulose vs. fiberglass batts, not
blown-in fiberglass.

re: -2
    
>>PS -- I bet within 10 years, someone will demonstrate a link between 
>>breathing fiberglass fibers and lunch cancer...
    
    	and I'm sure it will be even sooner when they can demonstrate a
    link between our cafeteria and lunch cancer... % }
    
    		-Ian

    re .44
    
    Right (thanks for paying attention). 
    
    Update: the carpenters are finished. Right now is have exposed studs
    and ceiling joists (?). I can put in fiberglass bats now or put up the
    wall board and plaster then blow in the cellulose. 
    
    In terms of ease of installation I would actually prefer the cellulose,
    but I was wondering what I was missing since people always seem to go
    to fiberglass when faced with a situation like mine. Hence the question
    regarding the pros and cons *once installed*. (No need to address the
    problems with installation here.)
    
    One other factor of interest. The structure is located very near a lake
    and seems to be exposed to very high humidity during the summer months.
    I am not too worried about the cellulose insulation in the walls but I
    would be concerned if the humidity would have an effect on the
    cellulose in the ceiling as there would be outside airflow from the
    soffits moving over it.
    
    One *more* factor. If some furry creature managed to chew through my
    soffits and get into the attic crawspace, would he be more or less
    likely to stick around with fiberglass vs cellulose?
    
    
    						thanks,
    						Mark

  So this house we just bought has an addition on the first floor that is a
bedroom sticking out with a flat roof (no second story above it).  The roof is
rubber.  It is an old house (even the addition is old) so the walls are lathe and
plaster.  The addition is not insulated.  Maybe it was originally a summer room
but now it is a year round bedroom.  Is there a way to insulate the ceiling?
Can we have a hole cut in the ceiling and cellulose blown in, and then create an
internal vapor barrier with the right kind of paint?  The roof will not breathe
at all, being rubber. Would it be more advisable to put a layer of some insulating
board such as Tyvek and drop the ceiling?  According to the tenant, the walls
are cold to the touch in the winter, so inspite of the assertion that it is
mostly the windows and roof, there has to be some loss of heat going on in the
walls.  The exterior is asbestos shingle, so I don't want to cut through it.
Suggestions?
	Linda

   <<< Note 8.47 by QUILLA::STINSON ""Linda Saisi Stinson...DTN 296-5796"" >>>

	   You might want to consider putting a pitched roof over the 
	flat one you already have.  The air gap you'd be adding would
	make a good insulator.

					Tim

    Assuming the ceiling is "reasonably" high, I'd be tempted to put up
    about 2" worth of foam insulation and cover it with 1/2" sheetrock.
    The foam will act as its own vapor barrier.
    
    Tyvek isn't insulation - it's just a high-tech paper substitute that
    they're using now to block air infiltration.  You may have seen large
    mailing envelopes made of it; extremely resistant to tearing.

	And what about the walls?  Will the asbestos shingles prevent moisture
	from escaping if we were to blow in cellulose?
		Linda

re .50:

The idea of a vapor barrier is to prevent water vapor from the living space
from condensing on the insulation.  Hence the siding shouldn't matter.
If the vapor barrier is inadequate and asbestos shingles are water-vapor
tight (which I doubt), then you could have a problem.

Blown-in insulation for wood shingled houses is installed by removing
selected shingles, cutting a hole in the sheathing, and blowing cellulose
through the hole.  Some kind of barrier (tar paper?) is put over the hole
and the shingle is reinstalled.  It may be considered dangerous to do
this with asbestos shingles, in which case the insulation would have to be
blown in from the inside (by cutting holes through the plaster and lath).

    I looked under insulation, doors and windows but found nothing applicable.
    PLease feel free to move this note.
    
    
    Where can you buy that V channel insulation that goes in the jambs of
    doors or windows?? It is plastic and in the shape of a V.

Most any hardware store or building supplies store will have it.  3M made
it first, but other brands have come out.  It's really a weatherstripping,
not an insulation.

			Steve

Your local electric utility company can provide the number for Mass Save, an
organization supported by utility companies (and maybe the state) to help
consumers consume less of our natural resources.  They will do a cheap
(free - $20.00, I think) "Energy Audit," which includes assessing your home's
ability to conserve water, gas, and electricity.  They give or sell that
V-shaped weather-stripping, insulation for light switches and outlets on
exterior walls, water tank wrappers, etc.

It's a good deal.

I've scanned all of the cement related notes in here and found no mention of 
the use of cement block as exterior walls in a home.  

I am in the process of purchasing a home which is constructed of cement block. 
The house is a ranch and while the thought of cement block walls conjures up 
some rather unattractive images, it is quite nice looking with a skim coat 
over the blocks and painted white.  

My question is: 
What sort of insulation might I expect from this type of construction?  

I have found a construction reference book which says that the block should 
provide R .28/inch which yields R 2.24 for an 8" wall.  The inspection takes 
place this Thursday and I'm told by that the inspector can tell me what other 
insulation is in place (ie. interior studs with Fiberglas).  
{I chose Paul Maida based upon recommendations in this conference; his wife 
Sandy has already been an enormous help...}  

Does anyone have success/horror stories with this type of construction?  The
listing sheet said something like "...concrete block construction keeps you 
warm in the winter and cool in the summer..." but you know how objective such 
statements are.  The current owner says that $1200 heats this 3 BR/7 Room house
for a year.  Is this good?

All comments welcome and appreciated...

Tom

    
    It should read "keeps you cool in the summer and cool in the winter."
    I have a block/brick ranch, 30 X 50. I also have single pane AL
    windows. I think I am loosing more heat out the windows than the walls.
    However, the walls are always cool. It cost about $1k/year with oil
    heat. This includes heating 900 sqft in the cellar. I'd do it again, no
    real need for AC in the summer :*)

    	CB

    
    I grew up (in the UK) in a house that was all cement-block construction
    and the first house bought was stone and brick.   Both were coooold,
    and the winter temps there are nowhere near as bad as here in the NE
    USA.  Many recent houses in the UK are constructed from an exterior
    brick skin, a 2-3" solid EPS insulation layer, 4" cinderblock, VB,
    battens & drywall.  These are very energy efficient.
    
    
    However, there's a lot less air infiltration than with wooden
    construction, so with an interior drywall over 2" of EPS insulation,
    (and a vapour barrier) concrete block should be close to your average
    wooden house. Damp through condensation can be more of a problem in
    concrete house - check around for slightly musty smells, indication of
    mould growth etc.
    
    At least you won't have to worry about termites, and exterior 
    maintenance costs should be lower.
    
    Regards,
    
    Colin
    
    
    

    My father was a contractor in Florida, where cinder block houses are
    the standard.  I don't know if New England termites are different from
    Florida termites, but in Florida protection against termites is a very
    good idea, as they are known to burrow up under the slab and begin
    feasting on your wall studs, roofing joists, etc.  My father has a
    regular maintenance against this, where the insecticide is injected
    underneath the slab around the outside edge of the house.
    
    Mark Lovik

    There are two schools of thought on insulating a concrete wall.  If
    you insulate outside (put the concrete inside the thermal envelope),
    then you have all the concrete mass as a thermal flywheel effect.
    It will take a long time to heat up and a long time to cool down,
    making for a stable indoor temperature.  This is generally seen as
    the more desirable option, although it's strictly personal preference.
    
    If you insulate inside, then interior temperature will respond much
    more rapidly to changes in the thermostat, more like a "normal" house.
    
    I think I'd do whichever is easiest and cheapest.  2" of high-R foam
    insulation will give you about R-12 to R-15 or something, plus whatever
    you get from the block, interior finish, etc.
    
    Insulating outside would put the foam outside the living space, a good
    thing in case of a fire (major toxic fumes when the stuff burns).

    
    -1,
    
    Good point.
    
    Depends on the type of roof construction too.  E.g. with a flush
    gable, you'd have to extend the roof out to cover the
    additional skin.  In MOH we didn't have that option, had to
    finish with an internal brick/batt skin and lost a lot of
    floor space as a result.
    
    That reminds me - did you see TOH last weekend, where they
    were making foundations in modular prefabricated EPS moulds?
    
    One thing that I was wondering - do they strip the exterior
    EPS where it shows above the grade or finish it?  Either
    way, it seemed like an excellent idea, and a way for a DIY
    person to build their own formwork.
    
    Regards,
    
    
    Colin
    
    
    

re .-1:
    
>    Depends on the type of roof construction too.  E.g. with a flush
>    gable, you'd have to extend the roof out to cover the
>    additional skin.  In MOH we didn't have that option...

Builders like flush gables because it's cheaper/faster to build --
for the same reason, many houses have nearly flush eaves.  Both are
a bad idea -- wide eaves and gables help keep rain off the sides of
the house and away from the foundation, which is a good idea in a 
damp climate, even if the walls are stone.  In hot sunny climates, 
very wide eaves and gables are a good idea because they help shade 
the sides of the house, reducing the cooling load.  


>    One thing that I was wondering - do they strip the exterior
>    EPS where it shows above the grade or finish it?  Either
>    way, it seemed like an excellent idea, and a way for a DIY
>    person to build their own formwork.

Stripping off the insulation above grade is often done, but it
eliminates nearly *all* the value of having insulation on the
outside of the foundation.  Most heat loss is above grade, and
nearly all the rest is within 2' from the surface of the earth.

So it's really very important to not strip off the above grade EPS.
It's also very important (in many areas) to do something to make sure 
termites do not enter the EPS below grade and use it to tunnel up
to some exposed wood.  So if there's a skim coat on the EPS, it needs 
to be applied both above and below grade.  

	Enjoy,
	Larry

I've noted that many cement block suppliers sell insulating inserts - pre-
formed styrofoam "chunks" which fit within the cavities of the blocks.
Does anyone know how effective these are in terms of increasing the R-value of
the block wall? I've never given them much thought when doing below grade
cement block construction with exterior foam insulation, but above grade
they'd seem to be advantageous if effective.

-Jack

    I would expect that these inserts are not very good.  The reason being
    that there is still a solid concrete path conducting the heat out of
    your house (or is it conductin the cold into your house).  Filling the
    gaps with foam doesn't break the conductivity.
    
    ICE blocks (which I'll be using for my house), are sort of "negative"
    cinder blocks.  Everywhere you see concrete in a cinder block, imagine
    styrofoam.  Everywhere you see air in a cinder block, imagine concrete
    and rebar (plus some extra concrete channels going horizontally.  The
    concrete forms a mesh inside the styrofoam wall.  The only continuous
    piece from front to back is the styrofoam.  The concrete is totally
    isolated.  This system doesn't even need a vapor barrier.
    
    Mage

I saw this done on This Old House.  Looked pretty neat.  However, there were
a couple of things that bothered me about it:


 - Cost - Being new, the time to do the job is higher (it took something
          like 12 hours to do 3 walls of foundation for room extension).
          This makes it more expensive to install.  Also, you have to use
          a concrete pumper, rather than the regular concrete setup.  Also,
          there were a gazillion little plastic ties used.


 - Strength - When they were putting it in, it was not as strong as the
              old-style forms.  Because of this, you had to watch for
              collapsing.

 - Termites - This was the biggest concern of mine.  The carpenter ants,
              and termites like to burrow up through the styrofoam and
              into the house.  Not good.  Because of this, they used some
              kind of chemical (pretty strong I would think).  What happens
              if this chemical doesn't work, or is found to be toxic down
              the road?

 - Looks - How do you beautify the styrofoam?  At least concrete does not
           look too bad, especially if painted a decent color.

Ed..

Cost of ICE Block is $12.00/block, which measures 48"x16"x8"

How do you beautify styrofoam?  You attach whatever facing you want to the 
molded-in mounting plates.  This could be as elaborate or simple as you like.
I plan on a chicken-wire base over which I will mold stucco (to get rid of the
boring straight lines).  Inside, I will attach wood-strips for real tongue-in-
groove wood paneling (not the 4x8 junk you get at the lumber yard).

We will pour in courses, so we don't have the sagging/leaking problem, and we
will build simply scaffolds on our very-sloped lot, so no concrete pump is
necessary (unless we get lazy).

    The TOH project didn't have any insulating chunks of 'foam in the
    foundation wall. It used sheets of foam, connected every 8" with the
    plastic thingies, in place of normal plywood forms. The foam stayed
    in place once the wall dried.
    
    Even though the TOH project required a pump due to the site, they
    said the technique with the styrofoam would have required it anyhow.
    Just dumping from the truck left too much of a chance for voids in the
    foundation which would probably not found until there was a failure.
    
    Edd

I also forgot to mention that the styrofoam generates toxic vapors when it
burns.  Because of this, the inside of the basement MUST be finished with
fireboard or the equivalent.  This includes crawl spaces, also.  Another
negative.

To be honest, the negatives almost seem to far outweigh the positives.

Ed..

    
    
    I need to insulate an interior wall surounding a laundry
    room on the first floor of my house. Has anyone here done
    this in the past?
    
    thanks for any tips
    steve

    
    Sound or heat?
    
    C
    

    
    SOUND!!!!

    Just putting in some 3.5" unfaced fiberglass batts will help a lot.
    If you want to get more elaborate (and if the wall doesn't exist
    yet), you can de-couple one side of the wall from the other by
    using a 2x4 top and bottom plate and 2x3 studs, staggered for each
    side of the wall ( | = stud):
    
    ----+---------------+---------------+---------------+----------
    	|		|		|		|
    		|		|		|
    ------------+---------------+---------------+------------------
    
    Then stuff in some unfaced fiberglass, and you ought to be real
    quiet.

    
    I should have included that this is an exsisting wall sheetrocked
    on both sides. 
    
    still looking for info	

Check out 1111.94 for soundproofing notes.

Rent a cellulose insulation blower and blow insulation into the walls.
You'll need a series of 1" holes on 16" centers to get the insulation
into each of the cavities.  

	Larry

    Our bathtub is in an outside corner of the house. This weekend I took
    down all the drywall adjacent to the tub (for replacement due to water
    damage).  Behind the drywall is a plastic vapor barrier and fiberglass
    insulation. 
    
    The vapor barrier stops short about 4" above the rim of the tub. 
    Is there some technical reason for this, or just laziness on the part
    of the builder, or what? I plan to replace the vapor barrier (damaged
    in the removal operation) and want to do the right thing.  
    
    					Val

The vapor barrier should go from floor to ceiling on all exterior walls and
maybe around the bath area.

When we were doing our addition, I was going to insulate myself. A friend suggested
that I call a couple of insulation companies.  Turned out they did it for about
what I would have payed for materials alone.

Anyway, when I was talking with them, I asked about vapor barriers on the
ceiling as well as the walls.  They both said categorically "A bad idea.'

They said that when a customer insisted, they installed the barrier, however within
a year after, that customer was complaining about mold and mildew, staining
of the ceiling etc. Their claim is that the house must breathe some, otherwise
the moisture will rise to a point where it will cause trouble.  Of course, if
you've installed an air exchanger, this shouldn't cause problems.

I asked about the possibility of the moisture collecting in the insulation. With
the r30 I have in my attic, there won't be a problem, so he says.  Time will tell,
I sure hope he's right.  Asking several other people, I discovered they don't
have a barrier in the ceilings either and have experienced no problems.

Maybe everything will be OK.

	Maybe I should stop worrying.


Chris

    RE: .19
    
    I don't know.....I sure would put a barrier on the ceiling too.
    Something else is going on here to cause the mildew. 
    
    Marc H.

    
    There should be a barrier down to the floor around a bath or
    shower.  It's a good place for warm and cold air to meet causing
    condensation.  Especially true if you plan to use a cement backer for
    tile.
    
    As regards the ceiling,  perhaps they were referring to the ground
    floor ceiling, where you do not put a barrier?  It only goes on the top
    floor ceiling.  Check the sheetrock that you are removing - some 
    installers use foil-backed sheetrock and leave out the vinyl.  If eps
    batt insulation or kraft-faced roll insulation is already installed
    then it isn't necessary to put up a barrier.
    
    Regards,
    
    Colin
    

    There should be some form of vapor barrier on the bathroom cieling.
    Kraft or foil faced insulation provides a vapor barrier but it is not
    as good as polyethelene since it has many more gaps. Water vapor will
    migrate from a high relative concentration to a lower one. In the
    winter that is from inside to outside. When it strikes a cold surface
    it will condense there unless it quickly moves out through some
    ventilation system. Moisture moving into a WELL ventilated attic may be
    OK but if yours is not that well ventilated, or a particularly large
    volume of moisture is released, or your attic has any kind of floor,
    you will have a problem if there is no vapor barrier on the bathroom
    cieling. The mold/mildew problem should be dealt with by using a
    properly vented (read: to the outside) blower to get the excess
    moisture out. Most attics are designed to vent only that moisture which
    gets through (barriers are not perfect) and what escapes through trap
    doors or attic doors. They usually cannot deal with no vapor barrier,
    or bathroom vents vented into them. They will eventually show
    water/mildew/structural damage. All of this is even more true for walls
    where there is no ventilation at all: condensation-city!
    
    If the insulators did not install any vapor barrier, at least make sure
    you attic insulation has kraft or foil facing.
    
    Larry 

Walls should have vapor barrier there's no doubt about this. now onto ceilings

if you have attic vents and it is properly vented there should be no vapor 
barrier, this also goes for basement ceilings. 

now if you have a house like mine where the fool who built it never put in attic
vents of any kind then I am putting up plastic befor sheetrock.

I know there's going to disagreements over this. :-)

Paul (who's been installing insulation off and on for at least 12 years) 

    
    I guess it all depends on what type of house and theory you
    follow.  To tight and everything stays inside the living
    space.  Not correct and you get drafts.
    
    I had FG batting in the house.  So I left it and put plastic VB
    on the  wall.  The roof area is vented using a ridge vent so
    I didnt put any plastic on the ceilings.  I have had no problems
    with moisture.  I think if there was foil backed in the walls I
    wouldnt have used and VB, but put a wrap on the outside when the
    house was resided.
    
    I have a section on the N. wall where in the mud room I put up the
    sheetrock and remembered the VB after...(memory laps).  But the
    rest of the N side was done.  I dont notice and difference.  But
    thats only an 8' section...
    
    You can always look at it this way.....you put up all that plastic
    as a seal.....The you punch all thoes holes into it. (elect,doors,ect)
    
    JD
    

    My understanding is that the VB is not primarily intended to be a draft
    excluder - that's what materials like Tyvek are supposed to do. It's
    purpose is to slow down osmosis - the permeation rate of airbourne
    moisture.  The drywall, plaster or masonry will continually soak up
    moisture from outside and release it inside.  The VB ensure that the
    absorption rate is always slower than the release rate.  In the days of
    plank sheathing, bituminized paper had the dual role of draft and
    moisture barrier, but I don't think you can use a draft barrier alone.
    For a start it's installation location is incorrect for a VB.
      
    I don't think there's a going to be a definitive right/wrong answer to
    this. My understanding of the *general* principle is that there should be
    a complete vapour barrier around the whole living space, which should
    be kept complete if the living space is extended in any way.  There is
    no need for a barrier in any internal partitions within this envelope.
    You have to have some air infiltration, so it's accepted that there
    will be some breaks in the barrier - such as outlets, although if
    these are correctly fitted the break will be minimal.   
    
    When I bought my house, which has 2x1.5 sq ft gable vents and soffit
    vents every 12", the inspector still brushed aside the blown attic
    insulation to check for a moisture barrier.  He commented that the
    basement insulation was incorrectly installed in places - the moisture
    barrier should face towards the living space.
    
    Regards,

    Colin

    

    re: .-1   no, no, no
    
    The purpose of a VB is to keep moisture *inside* the perimeter of
    the insulated area. This is counterintuitive to a lot of people,
    including *many* professional builders.  I worked as a builder in
    a past life and the misinformation in this area is astounding.  I
    would take with a grain of salt anything you hear from a so-called
    pro on this.
    
    The VB only comes into play in the Winter, first of all.  If you live
    in a very temperate climate you probably don't need one.  The problem
    in the Winter is that the dew point of the air in the house may very
    well be higher than the outside temperature!   Even an un-humidified
    FHA heated house which feels bone dry in the Winter (because the
    *relative* humidity is very low) can have enough humidity in it from
    breathing/cooking/bathing to cause this to happen.  If your
    relative indoor humidity is 33% at a temp of 69, then your dewpoint
    is 23 and if your indoor air contacts anything at that temp or below
    it will precipitate.  If this happens inside a wall, it can soak your
    insulation and rot your wood.
    
    It is also true that a secondary use of a vapor barrier is as an
    infiltration barrier.  This is completely unrelated to the above
    discussion.  If your external barrier (Tyvek et al) is perfect, then
    you don't need it.   But this is rarely the case, hence the indoor
    VB can help out here, particularly in renovation work where you have
    no control over the outside walls.

    re .-1
    
    EXACTAMUNDO!!!
    
    The idea is that you want to keep the moisture out of the insulation
    and structural members of the house to prevent rot and so on.  Take
    the walls and roof for example ... without a VB, moisture enters the
    wall or ceiling cavity ... as it passes through the insulation, it
    gets colder to the point where eventually it freezes.  Gradually the
    ice in the insulation renders the insulation useless.  Ventilation
    does not really solve this problem, apart from helping a bit of
    sublimation of the ice.
    
    In the spring when this mess thaws, the inulation becomes soggy,
    drowning the ceiling ... causing leaks and wet patches. Plasterboard
    gets softened and over the years becomes useless.  In a roof, the
    water will eventually evaporate off before the next season, but in
    the wall cavities, there isn't enough ventilation so the wood remains
    wet and eventually rots.
    
    Now, with a good VB the water vapour remains inside the house, where
    it causes other problems ... but none that cannot be solved simply
    by just improving ventilation.
    
    Stuart
    

RE:                      <<< Note 676.27 by CSC32::S_BROOK >>>

>    Ventilation
>    does not really solve this problem, apart from helping a bit of
>    sublimation of the ice.
 
A common practice is to install ceiling insulation without a vapor
barrier if the attic or crawl space above is ventilated.

Brian

    
    Hi,
    
    	I'd like to further this topic with a question of my own 
    regarding insulating an unheated garage. I'm considering 
    sheetrocking the remaining two and a half walls (garage doors consume
    most of one wall) in my garage. The back wall abuts the house and is 
    already sheetrocked. I want to sheetrock the remaining walls mostly 
    for aesthetic reasons.
    
    	My question is, should I insulate these two and a half walls? I am
    not planning on heating the garage and there are no living areas 
    adjacent to these walls. However, I can see a few good reasons
    for insulating. 1) If myself or a future owner decided to heat the
    garage, the insulation would already be in place. 2) On cold days when
    I need to work on the car, a spaceheater may be able to warm the garage
    up a little with the insulation in place. 3) The back of the laundry 
    room juts into the back of the garage a little bit. The water pipes 
    feeding the washer are built into this protrusion and so are exposed
    to the cold from the garage. When we have extended cold snaps, as we
    did a couple of weeks ago, the pipes freeze. If the garage was
    insulated, the garage may stay warm enough during these cold snaps to
    prevent the pipes from freezing.
    
    
    	Do you think it's worth it for me to insulate? If so, what R factor
    do you recommend?
    
    Thanks a lot for any advice.
    
    John M.
                                   

    Hello,
    
        I purchased a yr round cottage and am debating whether I do the
    blow-in insulation or tear down the interior wall and put up the rolls
    of insulation. Are there pro and con as far as cost goes and its
    heat effeciency?
    
    Your repsonses are much appreciated and thanks for your time reading
    this.
    
    Dave
    

    I just did it, but I may have had more proximate living space
    I was fininshing a new room OVER the garage. The garage itself was
    unfinished except for the wall that joined the house. By code then I
    had to install fire rated sheetrock on the garage ceiling, and 'normal'
    on the walls. I elected to install fire rated everywhere -not much more
    expensive but verrrry heavy- AND to fully insulate everything. I can,
    with a small kero heater, warm the garage to the point that I can work
    on the cars. Takes a little while, but I can get there.
    
    The cost for the insulation is not significant. Consider that should
    you EVER want to insulate, the alternative in the future is to first
    remove the wallboard. Put it in. 

    
    	Definately! Insulate it! You'll NEVER be sorry.
    
    				Kenny

    Re: -1
    
    I just read somewhere about a class action suit against Dow Corning
    related to R values with blown in insulation. What I remember is
    that when the temperature differences are large, the R value
    decreases with the blown in insulation. I believe it was related
    to the density factors that allowed air circulation through
    the insulation. This problem was supposed to be for attics rather
    than walls.
    
    If the walls were open, I would use batts or rolls. BUT if I
    had to tear down walls, I would give that a lot of thought.
    
    Joe

To me, a big problem with blow-in insulation is what happens when you open
up the wall, say to put an electrical outlet in.  You start getting insulation
pouring out the hole and there's no way to replace it at the top.  I did read
of a "wet fill" method which uses some sort of binder to keep the insulation
in place once it is installed.

If it were me, and if it didn't seem TOO difficult, I'd install batts AND
a polyethylene vapor barrier (something you can't do with blow-in).  You can
also get a higher R-value with batts than you can blow-in.

			Steve