Conference 7.286::home_work

    certainly you should have some sort of bridging if the joist span
    more than 8' or so.  I doubt that cross bridging would be agains
    code -- especially if metal.   The fire stuff sounds like nonsense
    to me.
    
    			George

    
    Do you mean this?
    
    		||----------||----------||
    		||          ||          || <-- 2x8 joists
    	 	||          ||          ||
       		||----------||----------||
		       ^
                       `-- 2x8 bridging

    If so, it's a great idea if there's nothing attached to the top and/or
    bottom of the joists. Such bridging eliminates warping of the joists
    from vertical, which would decrease the vertical strength of the
    floor. However, in a finished living area with strapping
    nailed to the joist bottoms (to which the sheetrock is attached)
    and subfloor nailed across the joist tops, bridging seems like
    overkill.

    The primary function of bridging is to spread concentrated loads to
    adjacent joists.  To this end, solid bridging is of questionable value.
    If the blocks do not remain tight (if they shrink, even a little)
    their effectiveness is reduced significantly.

    I would recommend metal bridging.  It is very easy to install from
    above.

    PL

    I have metal bridging now and HATE IT! Even though great care was
    taken too make them as tight as possible before they were nailed
    down, they still sqeak and make noises. Every time you walk around
    a room, you can here the creaks and groans of the bridging. I think
    the nails are sliding around inside the pre-punched holes in the 
    bridging. 
    
    I thinking about either replacing the lower nails with srews with
    a thick enough shaft to completely fill the prepunched hole in the
    metal bridge or cutting them out and installing solid block bridging.
    
    Charly

    I don't see any problems with slight shrinkage in solid bridging.
    The idea is to keep the joists from twisting under load; that's
    the only kind of load transfer you're going to get.  I can't see
    that a 1/8" gap here and there, if any develop, is going to matter 
    much.  

How come the "better" builders that I've seen tend to use the wooden cross
pieces rather than the metal ones?  I'd think the metal would be superior.

-mark

     I second the problems with metal bridging being noisy. I hate it.
    I've done everything I could think of to tighten it and it has only
    helped a little.
      There is no problem with solid bridging, it does use more lumber
    and takes just as much time for a pro to install as cross 1x3 bridging.
    This is why you will normally see the crossed 1x3 bridging in a
    home. The metal bridging is used by someone who is not as adept
    at cutting the cross bridging, in the long run the 1x3 bridging
    is cheaper if you can cut it quickly.
      There is absolutely no need for bridging if the joists have strapping
    run along the bottom as for sheetrock. The strapping keeps the joists
    from springing apart.
    
    					Kenny

    I was looking at some back issues of the magazine FINE HOMEBUILDING
    just recently and happened to read an article on floor bracing.
    It actually recomended not to do it at all since the flooring material
    actually does the bracing for you.
    
    It went into some detail on the why's. If you are interested I will
    photocopy the article and send it to you.
    
    Steve

    
re : < Note 864.8 by TALLIS::HUDSON >


    >It went into some detail on the why's. If you are interested I will
    >photocopy the article and send it to you.
    
    Steve, if it's not too much of a hassle I would be interested in a copy
    of that article.  I put in metal bridging for my 1st floor and was never
    very happy with it.  As a matter of fact I have often wondered if I 
    really need it at all.  Since I have a very low ceiling in the basement,
    I would kind of like to remove at least some of it if I don't really
    need it.

	-gary

    The only problem I can see with solid bridging is trying to fish
    wires through later.
    
    One vote for non-solid bridging.
    
    -f

    I would highly recommend solid bridging because for a novice it
    is much easy to install. Things to do: stagger the pieces and I
    would use a screw gun with drywall screws so as no to crack the
    plaster below. By staggering the pieces you are able to end screw
    the bridging except the very last pieces.
    
    As for the floor I would install 1/2" plywood, again with screws
    and then go over it with 1/4" Laun plywood. The reason is plywood
    has voids in it and a womans high heels will find this voids every
    time leaving a nice hole!
    
    Mike
     

    Ref. .4 & .6 about noisey metal bridging.If you can see it, check
    to see if there is a 1/4" between the two legs. If their is not
    that space, they will rub as the floor flexes. This is what usually
    causes the noise, not the nailing. I know because during construction
    of my present house, the man installing the bridging installed it
    all two close. i noticed the noise right away and easily renailed
    one of each pair of bridging legs, no more noise!!!

    
    
    
    	If you don't want to hear any squeeks down the road you may
    want to lay a bead of glue on all your subfloor sheets. I had a
    battle with squeeks and was told that your more expensive homes
    are built using glue and nails to hold down subflooring.
    
    	-Steve-
    

Now for something really different.  My father-in-law is a fanatic about 
building things that will last forever and be as solid as the pyramids.
He insists that the normal way that sub-flooring (plywood or whatever)is put
down does not provide support for the ends:

		    ----------------+--------------------
				    |
    joist -->   ====================|============================
				    |
			sheet 1	    |    sheet 2
				    |
		====================|============================
				    |
		    ----------------+--------------------
				---> <---
				no support
				   here

His solution is to use solid bridging in such a way that rather than
being staggered, they line up exactly where the sheets of plywood butt together.
Then the ends of the sub-floor can be nailed into the bridging, preventing any
movement.  The problem here is that when running plywood against the direction
of the joists, you need this bridging every 4 feet!  If you run the plywood
with the joists, you only need it every 8 feet, but don't you lose some
strength this way? 

Personally, I'm the lazy type and although this HAS to do a better job, does
it really do enough to justify?

What about tongue and groove plywood?  Would it help?  Is it overkill?

-mark

re -.1

> What about tongue and groove plywood?  Would it help?  Is it overkill?

	If you are one of the few who have the ability to get tongue and
	groove plywood to go together, it would certainly help.  I am,
	unfortunately not one of the few.  I tried to use t&g plywood for
	my decking.  However, after spending two hours trying to get the 
	first two sheets together gave up and just butt jointed them.
	After a layer of 7/16" underlayment on top of the 3/4" plywood
	decking and then 3/4" hardwood flooring, no squeeks....

	-gary

	Actually I tried it with my wife as helper.  Funny how they don't
	like to line up very well after they warp even the slightest.
	I didn't try a sledge hammer tho... Only a two pounder.

	I gave it a go a second time when I was putting in my second floor
	and only had marginally better success.  This time I kept it from
	warping, but I still had a hard time getting the tongue fully into
	that there groove...

	-gary

    Another tip for T&G Plywood is not to send home the nails or even 
    install nails near the tongue or groove until the next piece is in
    place. 
    
    Regarding the direction to run the plywood on the joists. The strength
    in plywood is built in the long way, the same as the grain on the
    outside. It is a lot easier to snap a strip a plywood cut across
    the grain the one cut with it. It should be installed the long way 
    (at right angles to the joists) and with T&G type plywood the joints 
    over the open parts of the joists are locked together by the T&G.

    I inadvertently installed a piece of plywood the wrong way in the
    floor in my tool shed and that section is noticably "softer" than
    the rest of the floor.
    
    Charly

So if T&G is less than 48", do you have to put your joists at something other
than 16"?  I guess the other alternative would be to add extra joists or
nailing blocks where the plywood butts, but isn't that a pain?

Sounds like good stuff, but how much does it cost compared to good old CDX?

-mark

but what about the shorter sizes vs. standard 16" joists?

-mark

-mark

    I'm planning a addition to my house and have a question about headers.
    All of the books I have referenced show how to frame headers for
    2x4 construction. Basically you put 1/2" spacers of plywood or whatever
    between the 2 header boards and you will have a flush surface on
    both sides of the header. I can't find anything that shows what
    you do if you want to come out flush with 2x6 construction. What
    is the common practice that is employed in this instance.
    
    Thanks,
    Jack

    I don't know if this is the right way, but it's the way I would
    do it, I would layer it this way.
    
    Ex: 2X8, 1/2"ply, 2X8, 1/2"ply, 2X8. this will give you a thickness
        of 5 1/2".
    
    
    Royce
    

    Thanks for the inputs. I took a tour through an in process developement
    this weekend and checked out a couple of houses. The upstairs headers
    were two 2x8's with only air in between them. The downstairs headers
    were three 2x8' with 1/2" plywood spacers between them. I guess
    I can do that.
    
    Thanks,
    Jack

    I'm going to be building an addition soon -- mostly
    a large open space (20' X 24') with a gable roof (cathedral
    ceiling).  I'm trying to decide about framing size for the walls.
    
    I'm trying to decide between 4" and 6" studs
    
    
    4"					6"
    
    Cheaper				Stronger
    Windows come framed			Costs more
     for this size wall			Xtra window jambs needed
    
    					More insultation possible
    
    Is 6" framing worth the extra money in both lumber and windows?
    
    What would YOU do (remember, this is with severly limited
    financial resources -- every penny counts).
    
    			George
    

    Some random thoughts -
    
    1) This is one of those areas where you may have to make a value
    judgement based on how important to you it is that you did it "better".
    The extra cost is probably not worth it in terms you can actually
    measure.
    
    2) Most decent windows and doors (Andersen etc) have extension jambs for 2
       x 6 walls.  But you pay more.  
    
    3) Insulation is an issue only if you stick with the traditional
    fiberglass stuff - if you go will some of the newer hitech solid
    foam board type products, you can actually get more R value in 2
    x 4 wall than a 2x6 fiberglass.
    
    4) With a one story building, strength is a non-issue. 
    
    
    
    

Assuming that you live here in New England, I would definitely go with the 2x6 
construction.  The cost difference is minimal, and the heating benefits should 
be noticable.

Note that the framing only costs a little more for 2x6, since you can put 2x6s 
on 24" centers instead of 16".  This works out to the same cost for wood per 
linear foot of wall, except you do pay more for the top and bottom sills and 
for window and door framing.

And yes, there are hi-tech insulation solutions, but on a cost-per-R-value 
basis, nothing can even come close to fiberglass.  You could cut the wall down 
to 4" with them, to save on the extension jambs, but the insulation would cost 
more than the extra jambs.

I would guess (total offhand guess) that it would cost you in the neighborhood 
of $200 to go with the extra insulation.  That's probably in the noise range 
for the expenditure of the entire addition.  I'm not sure how long the payback 
would be, it would depend on what you use for heating, but I'd go for it.

Of course, you might want to take me with a grain of salt.  The walls in my 
house are R26, and the roof R45.  On the other hand, we heated it with a cord 
and a half of wood this winter.

Paul

    If you're going to spend money anywhere, get the better windows
    and go with 2x4s. You lose more heat thru lousy windows than
    any size wall. Especially true if you plan on using alot of glass.
    I've never seen 2x6 contruction with 24" centers BTW.
    
    John
    

    I have (seen 2x6 on 24" centers).  But you need to use thicker sheathing.

    If you do go 2x6, go 16 on center, it's not that much more expensive
    and the added strenght is worth it. Extension jambs for your windows
    are not that big a deal, you can easily make them up yourself for
    pennys. 
     One thing that should have a major impact on your decision is the
    method you choose to heat your 20x24' space. If it's going to be
    heated with wood then 2x6 vs 2x4 is not that critical(you'll probably
    be plenty warm anyway), but if it's going to be heated with an electric
    source, you should go 2x6 without question.
    

    We're in the process of building a similar room (actually remodeling)
    and determined that because we have so many windows (almost all
    glass), the small area of wall that would be insulated was not worth
    the additional expense of 2x6's and extension jams.
    
    Window area has a lot to do with your decision, as a previous note
    mentioned.
    
    Pete

    
    my $.02 worth
    
    through personal eqperience i would recomend as stated earlier
    spending the extra money on Anderson windows. frame with 2x4's.
    if your insulating yourself, take the paper backing tab of the insulation
    and staple it to the 1 1/2" facing of the 2x4 as apposed to the
    traditional stapleing inside the 3 1/2" wall. this will provide
    a more air tight enclosure. remember to pull the paper up tight
    to the window frames also, and staple to the window frame. do the
    same on the ceiling joists. 
    
    steve
    

    I'd go with 2x6, 24" o.c.  It works out to exactly the same
    load-bearing cross-sectional area as 2x4's on 16" centers.
    Not that it's ever a problem with a house anyway - the vertical
    load capacity of a stud wall far exceeds any load that will
    ever conceivably be applied to it.
    Aside from being able to put in thicker insulation, putting 2x6
    studs on 24" centers also means you have fewer breaks in the insulation,
    which is a big win.
    In general I'd rather use fiberglass rather than foam whenever
    possible. Aside from being cheaper, it also doesn't give off
    toxic fumes if it caches fire, the way foam does.  For some
    applications, foam is undoubtedly THE thing to use, but I'd 
    use it only where fiberglass is unsuitable.
    Somebody raised the point of less support for the walls, so you
    need thicker sheetrock/paneling/whatever to make the wall feel
    "solid".  Maybe, depends on how much you notice things like that,
    I guess.  A firestop between the studs, midway up the wall, would help
    stiffen things.

    I have 2x6 24" o.c. walls with 1/2" sheetrock.  There's no problem
    at all with the span for 1/2" sheetrock.
    Also, making extension jambs is trivial and shouldn't even be a
    consideration.
    I"d go with 2x6 walls for the extra insulation.  I didn't even know
    houses in New England were built with 2x4 exterior walls anymore (except
    maybe for the foam core walls).
    
   

    2x6 walls aren't going to cost you that much more even if you figure
    in the extension jambs and thicker fiberglass; I definitely would
    go with 16"o.c.; it's just more "standard" than 24" (you're going
    to find that in a lot of places you'd have to add studs for nailing
    anyway, such as adjoining partitions, bathrooms (for convenience
    in hanging cabinets, etc), and window areas.   The number of verticals
    isn't going to be that many more if you used 16" centers.   Also,
    I'd question the availability/cost of 24" fiberglass: I couldn't
    find any when I spec'd out my addition (was just looking for cost
    comparison anyway), but I'll bet it would be priced higher per sq'
    than the regular stuff.   I did my 2-1/2 story addition with 2x6
    wall framing, and the rest of it all over-spec'd (like 2x12 floor
    joists where code called for 2x10)... I say the end result is much
    more rigidity (read: stability) and an added benefit is reduced
    noise transmission with 6" 'glass in the walls.   Also, I don't
    buy the argument made in a previous note that, just because you
    have lots of glass area you shouldn't worry about the R-value of
    the walls!   Buy the best windows you can afford AND build the best
    wall you can afford; heat will be lost through both no matter what
    you do.    Just because your windows only have an R-value of 3,
    doesn't mean that you should compromise on the walls...or the ceiling
    for that matter!
    

BTW, it's been my experience that 24" wide fiberglass is no more difficult to 
find, nor is it more expensive.

Paul

    
    I opted to go with 2x4 walls and concentrated much more on the air
    infiltration reduction (ie Tyvek and lots of caulking), lo-E glass,
    carefully applied vapor barriers and most importantly (since it's
    a cathedral ceiling) larger dimension rafters in the ceiling in
    order to fit thicker, higher R value fiberglass.
    
    -Rob

    Already thought about the ceiling -- the rafters will be 2X10
    rather than the necessary 2X8 to get more insulation and still have
    enought air space.
    
    				George

    
    
    	give it more.....
    

    i have a real predictament going on with the addition to my house.
    it is a 22 feet wide and 24 feet long. the ridge pole is the 24 length.

    the builder did not use trusses. Instead, he used 2x8 spruce for the
    rafters, and 2x6 spruce for the joists. from the ridge pole he has
    hung 2x4s every other rafter straight down to connect to a 2x10 running
    the length of the room parrallel to the ridge pole. this 2x10 is nailed
    into each 2x6 joist. the idea is to keep the middle of the joists from
    sagging once the ceiling is installed. 

                                ^
                               /!\
                              / ! \		/ \  2x8 rafters
                             /=====\		=    2x6 collar ties
                            /   !   \		!    2x4 lumber
                           /    !    \		+    2x10 lumber lengthwise
                          /     !     \		*    2x6 joists

    I'm sticking my neck out on this one but....
    
    You might want to talk to winter panel corp in brattlebor vt.  They
    are doing some interesting things with structural panels these days,
    and can offer some interesting cathedral ceiling designs that might
    not be that hard to build.  Of course taping the the joings in the
    cathedral ceiling will be a pain, but you will have that problem
    anyway.
    
    The idea that I am thinking of would have 3/8 OSB, laminated to
    some foam - you pick what kind - laminated to 3/8 OSB which is in
    turn laminated to a sheet of sheetrock or blueboard.  The R value
    is good, and unless the room is *huge* you should be able to span
    it with one panel on either side of a beam at the peak.
    
    If you need their address, drop me some mail.  I'm doing a post
    and beam house and have their info around here somewhere....
    
    - Rick

    I think your only hope of changing the inspector's mind is to get
    a licensed engineer to bless your carpenter's design.  If you can
    get a drawing of your carpenter's design with an engineer's stamp
    in the lower right corner to show to the building inspector, I
    would hope that he'd change his mind.  But he sounds like rather
    a twit.
    There are structural tables available that show the safe loads for
    joists and rafters and stuff (I think you said you tried to show
    some tables to the inspector) and before you talk to an engineer
    you might want to figure out the beam loadings and prove to yourself
    that it's okay.  But since the inspector seems to incapable of
    understanding such things, I think you'll need to get an engineer
    to state the case for you.
    Hard to follow your diagrams on the terminal screen - if I get a
    chance I'll print out a hardcopy and take a look at it.
    

Structural panels can be real nice, and can save you money IF you're having the 
additions built by a contractor.

You can make the roof/ceiling almost zero work, if you want a beamed ceiling 
look.  You put in a ridge beam, and then put in beams instead of rafters, 
spacing them 4 feet apart.  Then you just put the structural panels on top.
You can get the panels up to 12' (maybe even 16') long, and since they meet on 
the beam, you have NO seams to tape.  You just nail shingles to the top, and 
paint the bottom.  Because of the labor savings, if you're having someone 
build it for you, you can actualy save money by doing it this way.

On the other hand, structural panels run about $3+ a square foot, so if you're 
doing it yourself then it will cost you much more than standard construction 
methods.

Paul

    One question - what's the slope of the roof?

>    One question - what's the slope of the roof?

5:12, he said.

As far as I can tell from what you've said, the building inspector is a bozo.
The phrase that sticks in my mind from your note, and would confirm his 
Bozoness if it is in fact a direct quote is "It looks more like a truss that 
way."  I'm not sure about the member sizes, since I don't have any tables 
handy, but your builder's method of construction is fine, and as far as I can 
see is better, to say nothing of cheaper, than the building inspector's way.

Just another example of building inspectors that know NOTHING about building.

It reminds me of when we were building our house.  We were originally going to 
use hemlock beams, but discovered that finding hemlock large enough for what we 
wanted was very difficult, so we switched to white pine.  I was worried at 
first about using white pine, but the mill operators said they sold lots of 
white pine beams, and then we found out that Maine Post & Beam and Timberpeg 
both use pine for their beams.  I recalculated the sizes for the beams, and the 
next time I was by the building inspector, I mentioned that we were changing to 
pine.

"You can't do that," he said.

I tried to explain about how these other major companies used it, but he 
wouldn't listen.  So I went home and got brochures from the companies, which 
plainly stated that they used pine beams.  I showed them to him, and he hedged 
and said that he supposed that he'd have to let me use it, although he was 
still very much against it.  Just then, an older contractor walked into the 
office.  The inspector called to him, "Hey, Joe, would you ever use white pine 
for structual timber?"

"No Way," said Joe.

"See," said the building inspector, "He's been building in this town for 25 
years and he wouldn't use pine."

"Except for beams, of course," put in Joe.

"Whaaa..??" said the inspector, with a very silly look on his face...

"Yeah, sure," said Joe.  "You know that house I built up in such-and-such 
road?  That was all pine beams.  And that one over on that other road?  That's 
all pine beams too."

Somehow I just loved that silly look on the inspector's face, and that "Whaa..?"


Paul

    I'll check my framing books at home tonite but I believe your builder
    has constructed what amounts to a 'king-post truss' (copacetic).  I am
    curious as to how the 2x10 is attached to the 2x6 joists.  Since the
    joists are essentially hanging from this member, I would hope that it is
    connected by metal ties and not just toe-nails.

    Digression inspired by base note:

    The device that the 'inspector' specified for the center of the joists
    sounds like a grossly oversize 'strongback'.  A strongback is built
    on top of a long joist span to help keep the joists in the same plane.
    We always built them from two 2x4s:
                                        ----
                                        |  |
                                  ------| 2|
                                  |  1  |  |
    -----------------------------------------------------------------


                             J O I S T

    -----------------------------------------------------------------

    Lay out (1) with the correct joist spacing (e.g. 16" o.c.) and face nail
    it to the top of the joists.  Then toe-nail (2) to the joist and (1).
    This will draw the joists into the same plane.

    In your situation, the three 2x10s look more like an unsupported beam.

While we're at it, maybe I can get an answer that I can understand to a question
that I've asked before...

I'm sure you all know what a barn roof shape looks like:

                  __.__
               __/  |  \__
            __/     |     \__
         __/        |        \__
        /-\         |         /-\
       /   --\      |      /--   \
      /       --\   |   /--       \
     /           --\|/--           \
    /_______________|_______________\


Now, the beams in the roof structure (I don't know the correct terms) hold
the roof up, but they *also* hold the roof *together*, keeping the roof from
pushing the tops of the walls out!

How do you build a cathedral ceiling (leaving out the center beams) that will
not push the tops of the walls out?  I know that you can build a sturdy enough
roof to stay up, but I can't figure out a design that will cancel the lateral
force vector. 
 
Jim.

    re .2 the pitch is 5/12ths    
    
    re .4 the 2x10 in just sitting on top of all the joists. there are
    2 nails from directly above into the joists. I too asked why just
    nails and was told they were galvenized nails that would never come
    out. he said the heads would rip off before the nails would let
    the joists bow downward.
    
    john
    

	I second the suggestion to get a Professional Engineer to review
	your plans.  Actually, it seems proper to demand that inspectors
	never rely on their own expertize, but always require "professional"
	evaluation.  This would make their work objective.  They would
	merely verify that the work conformed to the plan.

	I suppose you need some kind of statement about the relative
	strenghs of the two roof styles with regard to snow load, wind
	load, and static structural load.  He or she has to compute
	tensile loads at the eaves on the ceiling joists, tensile load
	on the vertical members, sheer load on the rafters, and maybe
	the couple of other things I always forget.  Any fool can do
	this, but it takes time and you and I are not Registered
	Professional Structural Engineers, i.e. we are banana slugs --
	just ask your inspector.

	I was also wondering about how the 2 x 10 was attached to the ceiling
	joists (are those horizontal boards called "joists"?).  Evidently
	your builder believes the galvanized nails will hold the pulling
	load.

	Note that his design has two triangles sharing the vertical.
	Your building inspector's has three triangles around a box,
	sharing various members  --  probably as good.  Note also that
	your builder has penetrated the center space, precluding
	finishing a room.

    Opps - I noticed the 5:12 pitch after I re-read the base note.
    Well, just from vague memory, it seems to me that the 2x8 rafters
    are plenty big enough to support the roof on their own - none of
    this interior framing business has any bearing on supporting the
    roof load, its sole function is to support the ceiling.  Given that,
    I don't see why a "truss" is any better in this context.  It's my
    impression that the main reason to use a truss is to let you use
    smaller rafters.  
    Your builder is hanging the ceiling from the peak of the roof,
    which is a great way to distribute the load evenly on the rafters.
    I have no problems with that idea at all.
    I'm less excited about toenailing the 2x10 to the 2x6 collar ties.
    If I were doing it, I think I'd just extend the 2x4's down beside
    each 2x6 and nail through the 2x4's into the sides of the 2x6's
    so the load on the nails is basically shear rather than tension.
    
    That idea of the three 2x10's in a box looks like a total crock
    to me.  What use is it?  In fact, I don't see a real need for the
    2x10 at all, in either setup, if you can nail the 2x4's directly
    to the 2x6's.  
    
    I think either your carpenter's way of using a single center row 
    of 2x4's or the inspector's way of using two rows of 2x4's will work.
    And I'd leave out the 2x10 business altogether.  But all this is 
    just guess - an engineer's opinion is the only one that is likely 
    to mean anything.

    Isn't your design the same way that Maine Post & Beam does their
    saltboxes?  (I think they do capes differently),  but their saltboxes
    have a beam coming down from the peak, to meet the collar ties which
    extend horizontally to the rafters.  Whats the difference between
    yours and the ones they do?  Is it a question of the size of the
    wood you're using?  Would your inspector allow MP&B to build in
    your town?
    

Steve's point in .8 is well taken - the 2x6s on the bottom, the 2x10, and the 
2x4 hangers have nothing to do with the roof loading.  Just the rafters and 
collar ties provide the strength to the roof.  The other stuff has nothing to 
do with the roof load, but is only there to hold up the ceiling.  And I would 
certainly think that the 2x4s and the 2x10 ought to be able to hold up a few 
2x6s and some sheetrock, which is all they are doing.

re: .5

Jim, as far as I know, the only effective way of making a gambrel roof (or any 
other roof) without internal supporting members is to make a load-bearing ridge
beam, and then hang the rafters off of that.  That way, the ridge beam supports 
the middle and there is no tendency to push the walls out.  You wouldn't need
beams at the two side roof angles, two rafters crossed and nailed together will
be stiff enough, and will have no tendency to fall in since both ends are 
supported.

re:.7

>	Actually, it seems proper to demand that inspectors
>	never rely on their own expertize, but always require "professional"
>	evaluation.  This would make their work objective.  They would
>	merely verify that the work conformed to the plan.

PLEASE, NO!!  I don't want to have to go get an expensive engineers stamp to 
put up a railing on a porch.

>	Note also that
>	your builder has penetrated the center space, precluding
>	finishing a room.

He pretty much precluded finishing a room up there by the rest of the 
construction, also.  Given that the ceiling rafters are hanging from the roof 
rafters, if you wanted to put in a room over the garage (30 psf live load), then
you'd have to make both the roof rafters and the ceiling rafters bigger to 
carry it.  

This is of course not to mention the fact that with a 5:12 pitch, a 22 ft wide 
building will have 11 ft on each side, giving less than 5 ft of headroom before 
you subtract the space taken up by the roof and ceiling rafters.  :^)


Paul

    Fresh from a discussion with a builder....
    
    The only problem with beams 4' oc, and laying the panels on the
    top of the beams is that you get stuck not having enough panel for
    the ends.  He recommended splitting the difference over the beam
    - so you don't have to tape - and then using a panel with OSB on
    both sides to frame out over the edge of the roof. This is not too
    much of an issue in this example, but makes things really easy in
    the case of a P&B house.
    
    
      osb ------------ ---------  osb
                 foam | foam | |
    	     	      |      | |
      sht rock ------- ---------  osb                           
                   |    |
                   |beam|
        inside     |----|    overhang

	re: .10's re .5

	Maybe instead of an expensive engineer's stamp, we can get
	designs checked for load-bearing capacity by computers.
	There must be some way to get inspectors to butt out.

RE .5  (Gambrel cathedral ceiling)

    The advise given in .10 (use a ridge beam) is the general solution
    for cathedral ceilings with straight rafters (single pitch roof).
    If your 'cathedral ceiling' is really, in fact, a room under the
    roof, then you have a variation of a normal cathedral ceiling and this
    solution will work for you.

                                   -
       This:                   -   B   -
                           -               -
                          -                 -
                         -                   -
                        -                     -
                        -----------------------

                                   -
       is the same as:         -   B   -
                           -               -
                        -                     -
                        |                     |
                        |                     |
                        -----------------------

   
      But, if you                  -
      want to do this:         -   B   -
                           -               -
                          -                 -
                         -                   -
                        -                     -
                        |                     |
                        |                     |
                        |                     |
                        -----------------------

    then you have a more complicated situation.  You have three surfaces
    that must be held in place.  If the room is not too long, you can rely
    on the end walls to hold the system together.  Otherwise, you must do
    something to keep the 'elbows' from flexing.  You can do this by
    placing another beam at one of the elbows on each side of the room
    (you need not do all four; doing one pair reduces the system to one
    of the simple cases).

    Another solution is to make the elbow in the roof rigid.  You do this
    by putting blocking in the elbow and plywood gussets on both sides.
    I've seen this done as an alternative to the ridge beam in my first
    picture.  The rigid elbow causes your split rafters to behave as a
    single rafter would.  You will have to calculate the moment at the
    elbow in order to determine the proper lumber size for the rafters
    and the size and thickness of the gussets.  The American Plywood
    Association will send you structural information about plywood for
    free.  I'll include the address and name of the publication tomorrow.

    Note that you need to add structural stiffness for each 'elbow' in
    your roof between the bottom and the ridge.  If you have one elbow,
    you can use a beam or gussets. If you have two elbows, you will need
    2 instances of beams or gussets.  An A-frame has no elbows...needs
    no extra support.  Bow houses have an infinite number of rigid elbows.
    BTW: have you considered a bow (a/k/a gothic arch) for your situation?

RE: .10, .12

Thanks...

So with a load bearing ridge beam, all the weight of the roof is supportted by
the end walls???  That could be quite a load! especially on a say, 30 x 60 foot
roof. 

ok, I get the idea of the gussets...  I already knew the corallary to the
multipitch roof, but hadn't thought it out that far.  It seems like the moment
on those gussets would be pretty large, especially if you had to span, say a 30
foot building from wall to wall.

Jim.

PS  Has anyone ever 'builtup' beams out of multiple 2x*'s.  I might have
to do this for the ridge...  Would it help to make the side beams like this,
maybe bend them around the gusset where the roof changes pitch?

RE: .13

==>  So with a load bearing ridge beam, all the weight of the roof is
==>  supportted by the end walls???  That could be quite a load! especially
==>  on a say, 30 x 60 foot roof. 

    No problem (he says).  Wood is very strong in compression.  Simply
    include a suitably sized 'post' (multiple studs) in your end walls.
    Avoid openings (windows, doors) under the beam.  Otherwise you will
    need hefty headers over the opening, etc.

    A 60 foot long beam is another matter.  I was once charged with
    designing a roof for a 24 x 36 garage.  The owner did not want any
    posts in the garage yet he wanted some useable space in the 'attic'.
    I considered using a 36 foot glulam beam but it would have been huge
    (I don't remember exactly but it was something like 6 x 24) and
    expensive.  I designed a truss that is still standing after 6 winters.
    For a 60 foot span I think you are talking about a BIG steel girder.  

==>  ok, I get the idea of the gussets...  I already knew the corallary to
==>  the multipitch roof, but hadn't thought it out that far.  It seems
==>  like the moment on those gussets would be pretty large, especially if
==>  you had to span, say a 30 foot building from wall to wall. 

    On the example of gussets that I saw (10 years ago so the memory is
    somewhat cloudy) the span was at least 30 feet.  The rafters were
    2 x 8, I think, certainly no more than 2 x 10.  The gussets were about
    3-4 feet long (seems to me that 4' would be a natural); they were as
    wide as the rafters at their ends and had a straight chord across
    the inside of the elbow so they were wider in the middle.

    If you are, in fact, building a 60 foot long room with no posts,
    you should be looking at some sort of truss or a rigid wall/rafter
    member.  I've never been a fan of gambrels (strictly a matter of
    personal opinion, of course); on the other hand, I think a gothic
    arch would be an elegant solution, structurally and aesthetically.

    PL

RE: .14

You're being *very* helpfull!  What I want, is a large space for a boat shop, so
I need to have the extra open space vertically that a gambrel gives. An arch
would not be bad, but I'd like to have a lot of windows/skylights up there for
the light as well.  I would think that putting skylights in a curving arched
roof would be tough.  Maybe I could build arch rafter beams, and build up the
(multipitch, but flat surfaced) gambrel roof on top of them.

What do you think?

Jim - Ain't this fun... 

    I did a big garage 36' long where the owner wanted a no posts /
    no trusses wide open attic for a studio.  Plus he wanted a huge
    almost full length dormer on one side.  So we needed a bearing ridge
    beam - the architect decided to use a 6x12 steel I beam.  Glulam
    or microlam beams were considered but as .14 states they would have
    been enormous, if even possible.
    
    

    
    re .14, .16 ...
    
    	There is a good way to build a cathedral ceiling without collar
    	ties, or center poles.  The method is called a scissor truss.
    
    	It is very functional and gives lots open roof space.  It looks
    	something like this:
    
    
 			peak ->	 /|\  - Roof rafters 2x10's
    				/   \
    			       /     \ 
    			      /       \
    			     /         \
    
    	given that this is the outside portion of the roof system you
    	then build a scissor system inside of it that looks like this:
    
  			Peak ->	/\
    			       /\/\
			        /\ 
    			       /  \  - 2x10's
    			      /    \
			     /      \
    
    	It is hard to draw this on the tube but I think you can get
    	the picture.  The scissor and the outside rafters meet at the
    	vertical wall.  Loading on the roof is evenly distributed and
        the structure is very sturdy.  You do loose some interior room
        but nothing dramatic.  I have seen this done on capes that were
    	26' wide with an open ceiling with no breaks or center supporting
        walls.
     
    	As for spanning large open areas such as garages 34' wide, you
        can use a prefab webbed truss system.  They must be engineered
    	for size at the factory, so you width measurements must be correct.
    	There is also a 3-4 week wait to get them made. They cost 
    	@ 2.80 /lin.ft.
    
    	You can also use a truss called a TJI.  These are plywood 
        I-beams that look like:
    
 				=====    
    				 | |
    				 | |
    				=====
    	These come up to 60' long and in various widths.  You can also
        cut these on site, so if your measurements are off a little,
        you can compensate.  You can also cut holes in them for piping
        without destroying the strength of the beam.  Most lumber yards
        that carry them will do a computer analysis on your structure
        to determine the width of the beam needed.  They will also give
        you a print out of how the beams are to be spaced/layed out.
        I am using these on a home I am building to get a clear span
        in the basement, and to so away with bearing walls on the first
        floor.  They are @ 1.80 /lin.ft.

    re .17 - I like that scissor truss...
    
    another possibility that occured to me was to find a way to buttress
    the walls, maybe if other rooms were possible/desirable in addition
    to the large open room with the cathedral ceiling you could locate
    them outside the bearing walls to balance or take out some of the side
    loads.  I think Jim mentioned a boat shop, if storage sheds or office
    space were needed that might be an alternative - after all, the
    flying buttress was invented to retrofit cathedrals that needed
    the side wall support...
    
    (obviously not to scale)	/\
    			       /  \
    			      /    \
    			     /      \
    			    /        \
    			   /          \
    			  /            \
			 !		!
    			 !		!
			/!		!\
    		       / !		! \
    		       ! !		! !
    

    Where can I find design info on scissor trusses?  No, I don't
    want to by pre-made trusses.
    
    Also, if i don't build trusses ( I probably won't, as I'm planning
    a loft), I'll need collar beams.  How *does* one anchor a
    color beam into the top plates? Or do you just bolt it to the
    rafters?  My spouse isn't keen on boxed in beams, so my
    original plan of a 2X8 on either side of the rafter is out.
    
    Where does one find 20' X 4" x 8" (or whatever) solid beams
    for this application?
    
    			George

    re .20
    
    That's what I thought -- any pointers to design tables for the things?
    
    My original plan was pairs of 2X8 (one each side of a rafter)
    4' o.c.   My wife thinks this will look odd, and doesn't like
    them boxed in either.  Span is 20'.
    
    
    				George

    Any one know about gussets?
    
    I'm building an addition on piers:
    
    
    
    
     	  ||	||    ||    ||
	  ||	||    ||    ||    		<---joists (2X8)
    ______||____||____||____||______
    |        |         |
    |        |         |			<--beam (3 by 2X12)
    |        |         |
    |________|  gusset |______
	     \         /
	      \       /
    	       \_____/
    		|   |				<--posts (6X8, 8' apart)
    		|   |
    		|   |    
    
    		|   |
    	     ___|___|___		<---footing (concerete).
    
    
    There needs to be some kind of gusset or bracing to keep the posts
    perpendicular to the beams, and to keep the beams from falling over.
    
    I thought that steel gussets might do the trick -- how available
    is that sort of thing?  Do they come in standard sizes?
    
			George
    
    

    
    
    	re .19
    
    	I don't know off hand where you would find a design for a
    	scissor truss.  I have seen them on a few homes, I'll try to
    	get some more info.
    
    	As far as where to get beams, it depends what you want
    	Oak, Fir, Pine, or gluelam.
    
    	Most large lumber yards carry the Fir and Gluelam in a variety
    	of lenghts.  Oak beams are expensive, heavy, and hard to work
    	with.  The gluelams are nice for the contemporary look.  
    
    	I do know a place where you can get nice pine beams at a 
    	reasonable price.  A mill in Atkinson, NH ( thats just east
    	of Salem, NH, and just north of Haverhill, Mass)  Feuer Lumber
    	Company cuts their own beams.  The mill has been in business
    	for years, I worked there in high school.  Maine Post & Beam
    	buys a lot of their beams from this mill.  If you are near there
    	and are looking for beams I'd suggest you check them out.
    	They are on Rt 121 in Atkinson, the only main road in the town.

I just have to put in a plug for Feuer Lumber.  When we built our house, they 
were the ONLY people we dealt with that were totally reliable.  I'd call up 
John Feuer on a thursday afternoon, and ask if I could get some beams delivered 
on Friday 'cause I really needed them on the weekend.  John would think a 
minute, say 'sure', and I could hang up with never another thought as to 
whether the beams would be there in time.

Couldn't say enough about them, they're a great, family owned, run-the-old- 
fashioned-way sort of business.

Paul

    Why are you putting the floor rafters ontop of the 2x12's? Why not
    attach them to the face of the 2x12's ( same level) and make the
    piers high to maintane the proper height.
    
    Use "TECO" connectors as they add to the strength of the conections.
    
    Mike
    

    Where is Feuer Lumber ??  From previous notes I assume somewhere
    in the Fitchburg Townsend area.
    
    I live in Nashua and would like to know how convenient they are.
    Nothing like good word of mouth advertising.
    
    -f

>    Where is Feuer Lumber ??  From previous notes I assume somewhere
>    in the Fitchburg Townsend area.

Directions are in reply .22

    Well folks, after many weeks of nervious, I've got an answer. While
    talking to my boss about my problem he suggested "Why not talk to
    an structural engineer?". Guess thats why he is the boss!
     
    To find one of these people is a quick
    lookup in the yellow pages under engineering. The one I choose
    was Prestige Engineering in Pepperall. 
    
    As I explained my problem, they told me it was a $750 fee to look
    at the house. I then asked them if i could supply diagrams to save
    them coming out. They said sure. So I went home and drew up diagrams
    from the top and the sides, and then took a couple of Polaroid
    snapshots (I knew i would use that camera again some day) and brought
    them over the next afternoon. Although the engineer had never seen
    anything like it, he decomposed the structure and then started cranking
    out the formulas for each peice of lumber, corner, nailing technique
    etc. . He got through the initial rafter loads in about 45 mins.
    It was getting late and I said i would call him the next day. THIS
    WAS A MISTAKE. When I called the next day, he had most of the work
    completed, but had another 4 hours on the project. I then told him
    I wasn't looking for a $20 solution to a $5 problem. If I had looked
    over him the whole time, I would not have let him play games checking
    shear loads on each nail. This would have saved me at least 
    2/3rds the total cost of $360. I found out the structure will work,
    but it needed some extra lumber added to it. I'm still ahead $100
    on the lumber, plus hours of labor to rip down the strapping
    , the old joists, and then replace the joists with 2x10s. before
    putting the strapping back up. 
    
    Anyways, If you are going to add an addition that costs over 10K,
    spent a grand and get an archutect to design it for you in the first
    place. You'll sleep better for it, and save that much along the
    way. 
    
    john
    
    p.s. thanks for all the replies. 
                                                                     

    I guess this as close as I can come to the topic without creating
    a new note, so here goes.
    
    I will be installing a 6' slider in an area which consists of wall
    and a window.  I will have to rip out the plaster, remove the window,
    remove the shingles and move/disconnect an electrical outlet.  Then
    I have to prepare the rough opening.  How can I take out a 6-7' section
    of this wall (back of house, load bearing)?  Will removing the studs
    in this area while I put the header in cause the surrounding ceiling
    to make a nosedive towards the basement?  Should I put up temporary
    supports?  I'd hate to drive nails into the hardwood floors but
    if it keeps the ceiling up...

    Phil

I plan to do this very thing soon too.  What I recommend is rather than nailing 
anything to the walls, put in a plank against the ceiling (across the joists) 
and brace it to the floor using a few 2X4's.  This should provide the necesary
support while you work.

btw - I did this in another house and found there was 0 sag even when such a 
large section of wall was removed.  After all, there are big sheets of plywood
holding the ceiling to the upper floor.

nonetheless, I'd feel safer with the bracing.

-mark

    re: .5
    
    There is no second floor on the house so I guess the load on my
    walls would be even less.  I guess I'll build the temporary support
    and then brace it to the newly opened wall.
    
    Is there anything else about this slider installation I should know?
    I know that the bottom should be well caulked.  Nothing else to
    worry about?  This just sounds too easy so I'm worried!
    
    Phil

    I feel like such a doomsayer sometimes, but here's my .02
    anyway.  We just had two large side-by-side windows replaced
    with a slider and the major problem was with making sure the
    slider was level where the rest of the house wasn't.  Since
    the slider has to be perfectly level to open and close properly
    it was by far the trickiest installation of all the windows done.
    
    It's well worth it - looks great.
    

    > Should I put up temporary supports?  I'd hate to drive nails into
    > the hardwood floors but if it keeps the ceiling up...

    After the plaster, etc. has been removed, but before cutting out the rough
    opening, place an 8-foot 2x6 (or so) against the studs above the area to be
    removed, and spike each end to a permanent stud on either side of the rough
    opening. Then nail through this into the upper portions of those studs
    which are to be removed. This will support the wall and ceiling when the
    lower portions of the studs are taken out.

    Russ

    btw - the Reader's Digest Home_Improvement_Guide has a detailed section
    explaining how to determine the size of header supports needed when load-
    bearing and non-load-bearing walls are removed.

A couple of framing questions...  

btw - might be have a FRAMING keword?  Maybe single note with framing questions?

#1

Header sizes.  I suppose if I had a copy of a building code I could figure this
out myself.  I need to make headers for an 8' span.  I know if this was carrying
a rood I'd need 10" material.  However, it's only a side wall and only suppost 
the second floor wall.  The easy way would be to simply use big stock, but I
want to put a trapezoidal window over and want to keep the gap minimal. Since
it IS a 6" wall, I can use triple studs.  My gut tells me I could get away with
2X6's, but I want to be legal as well...

#2

I'm doing a roof with 12" rafters and from my calculations about 8" of the
rafter will sit above the wall.  Is there any type of internal bracing needed
or required to stiffen the roof?  I was thinking about cutting blocks to fit
between the rafters (and still allow air flow), but was wondering if there is
a more correct way.

commentary...

I just put up some walls over the weekend and tried building a complete section,
including the plywood, in one shot, much to the objection of my father-in-law.
I told him this is the way it's done these days and went ahead.  As usual, he
was right.  I got the wall up ok, but there was around a 1\4" error which meant
that where it butted up to the rest of the house the sole plate didn't quite
touch.  This in turn caused a 1/4" overhang on the foundation which then meant
some extra work putting up the wall on that side (ie filler).

My F-I-L's theory is that since the plywood literally cements the wall into an
inflexible structure, you're far better off getting the skeleton in place first
and then adding the sheathing later.

thoughts?

-mark

    Re, Building a whole wall section and then standing it up. 
    
    Yes, this is the common and easy way to do it assuming you have the man
    power to put it up. What probably went wrong with yours is either you
    didn't square the frame before you put the plywood on and/or the wall
    you were trying to meet wasn't plumb. 
    
    To square the wall you measure from corner to corner and adjust the
    frame until they are equal, then apply your plywood. Other tricks are
    to snap a chalk line on the floor where the inside of the wall should
    go, build the wall with the bottom of the shoe plate on that line, and
    before standing the wall up, toe nail thru the top of the shoe plate
    into the floor. When you go to stand the wall up, these nails act like
    a hinge and hold the bottom of the wall in place. 

    Charly    

    Just heard an interesting story.  I hope I get some authoritative
    responses or references.

    Seems this developer built 20 houses on the shore of Lake Erie - ten
    were 2x6, ten were 2x4, with commensurate insulation.  He then simulated
    identical living environments in all of them - opening doors and windows,
    taking showers, etc. - for a year and compared heating costs.  His
    conclusion:  take the money you save on 2x4 construction, put it in the
    bank, and you'll have more than enough to pay for the additional heating
    costs.  (A caveat:  this was in the mid-60's with its cheaper oil.)

    Jon Reckard

>        Seems this developer built 20 houses on the shore of Lake Erie - ten
>    were 2x6, ten were 2x4, with commensurate insulation.  He then simulated
>    identical living environments in all of them - opening doors and windows,
>    taking showers, etc. - for a year and compared heating costs.  
    
    He built 20 houses for this purpose?
    He simulated identical living environments in 20 houses?  He heated
    20 houses for a year, opening doors and windows, and taking showers
    in all of them?
    Who funded this project?  The government?
    

    As far as the header goes, I think I would pack up 2x8's with 1/2"
    plywood between.  giving you something like this:
                                  
                    |--|-|--|-|--|
                    |  | |  | |  |
                    |  | |  | |  |
                    |  | |  | |  |
                    |  | |  | |  |
                    |  | |  | |  |
                    |__|_|__|_|__|  
    
    
    as far as supporting it I would go with this:
                        double top sill
                                \
              -------------------------------------------------------
              -------------------------------------------------------
              -------------------------------------------------------
                |  |  |                                      |  |  |
                |  |  |         2x8 packed header            |  |  |
                |  |  |                                      |  |  |
                |  |  |--|--|--------------------------|--|--|  |  |
                |  |  |  |  |                          |  |  |  |  |
                |  |  |  |  | \                        |  |  |  |  |  
                |  |  |  |  |  2x6 studding            |  |  |  |  |
                |  |  |  |  |<------rough opening----->|  |  |  |  |
    
    
    this is the way I would go, but i'm not sure of the weight it will
    be carrying, you might have to go with 2x10's....
    
    Fra

I built some headers for a 6' door using packed 2X10's (using the 1/2"
plywood filler).  In my case I don't have that kind of weight to deal with.
The one thing I did differently is that rather than using 2 cripple studs on
each side of the header I only used one.  

I KNOW that 2X8's would do it, but if possible I'd like to go to 2X6's to
reduce the space between the picture window on the botton and the glass on top.
I was just wondering is anyone knew the code.
e
-mark

>    Who funded this project?  The government?

     I found it difficult to believe myself.  But, assuming that the
     info-gathering was legit, what do people think of the results?

I broke down and took a look at the State Building Code at the local library.
Much to my dismay, it said nothing about sizing headers for triple widths.  It
only talked about doubling them.  For a book that goes into gory detail about
taking earthquakes, windshear, etc. into consideration you'd think they would
say more about headers.  All they had was 1 table listing 2X6's -> 2X12's
and three categories of support: roof, second story, non-supporting.  Seesm to
me there could be some finer divisions here too.  What about the second floor
windows on the side of you house (not holding up the roof but still holding
up the side wall).

Anybody got any ideas who to call?  If I get around to it, I'll call the state
house, but I doubt if it'll do any good.

-mark

    Mark...why not talk to your Building Inspector...after all that
    who will give you trouble if you don't meet the code ?
    
    john mollica

Actually I called him and he told me that without the details about the types of
loads being supported it was hard to tell me over the phone.  Just telling him 
it wasn't load bearing wasn't enough...

frustrating!

-mark

I'm puzzled about the reference to a 12" beam.  You can easily carry up to 8
feet with a beam made out of 2 2X10's.  It's even in the building code.

-mark

    If you really need to know I'll look up the size of the wooden beam,
    as drawn by the engineer on the blueprints. I was writing from 
    memory.
    
    The wall that was removed was carrying a beam (maybe 6X6, again
    from memory, only partially exposed, hard to measure). The concern
    was to support this beam that held up the second floor, and the
    gable end of the new addition, which was also attached to the
    old part of the house above the wall which was removed.
    
    Too complicated for me to figure, so I let a couple of Pro's
    figure it for me.
    
    Anyway, I had it inspected and no problem.     
    
    These builders also used a steel beam in the garage, eliminating
    the need for a lally column. (unless I start to live in the room
    above the garage)
    
    A steel beam was also used to support the floor of the addition.
    
    Point being, a steel beam could be an alternative to wood in 
    certain situations.  I see alot of them used in new construction,
    where the builder is trying to create an open design.
    
    Steve
    

What are people opinions of the correct method of using joist hangers.  Now
that I've already put up most of what I plan to, it's a little late, but what
the hell.

I guess my main question is are they sufficiently strong enough to not have to
actually worry about securing the joist to the wall itself?  If so, what size
and how many nails should one use?  The nail holes aren't big enought for really
large nails and since you're often going into a single piece of woods you don't
need much length.  Also, there's LOTS of nail holes and do you need to fill 
every one?

Personally, I get paranoid and after securing the joist hangers to the wall
with 6 8d nails I then toenail the joist (in my case I'm talking 2X10's) with 4
16d nails. 

-mark

    Yep -- ya gotta toenail it in too, just as you're doin'

    RE: -.1
    
    Why?  I've never used joist hangers but it sounds like a LOT of
    nails.  Does toenailing keep the joist from twisting?  Won't the
    hanger do this?  Damned if I know, just wondering?
    
    Phil

    Joist hangers look incredibly mickey mouse but structurally the
    idea is to put a shear load on a bunch of nails.  The strength of
    nails in such a config is incredible when the nails are driven into
    the joist to which you are connecting (the band joist) all the way
    to their heads so they can't bend.  You don't need to fill all the
    nail holes. 6-8 16d nails ought to do it.
    
    

    I just finished building a 10' x 12' shed and the floor deck is
    built of 2x6 joists fastened to a frame of 2x8's as shown below:
    
                   ----------------------------
                   |  |  |  |  |  |  |  |  |  |
                   |  |  |  |  |  |  |  |  |  |
                   |  |  |  |  |  |  |  |  |  |
                   |--------------------------|
                   |  |  |  |  |  |  |  |  |  |
                   |  |  |  |  |  |  |  |  |  |
                   |  |  |  |  |  |  |  |  |  |
                   ----------------------------      
    
    I used joist hangers throughout and I used all the nail holes, both
    in the joist and in the frame to which the joist is fastened. The
    nails sold for the job are made by Kant Sag for their hangers. These
    are short (about 1-1/4") nails coated with some sort of glue so
    they won't penetrate a 2" x N" board but neither will they tend
    to vibrate or work their way out. I don't think toenailing is necessary
    since there are at least 4 nails holding the joist into the hanger.
    
    Dave 
    
    
    

re:-.2

You can't use 16d nails because the holes are too small and that's the reason I
toenailed.  8d nails are nowhere near as strong as 16d and made me nervous.

I suspect that for a deck it's probably fine to skip the toenailing step, though
I doubt if I would (besides, I had just bought an Estwing Framing hammer and
needed to get some use out of it).  Anyhow, as part of a house, holding up
several floors, I felt better toenailing.

-mark

    I've seen a lot of jobs where fairly long (2") roofing nails were
    used.   Seems to make sense - big heads to keep from pulling through
    the hanger under tension - galvanized to minimize rust and corrosion
    at metal-to-metal contact points.
    
    What you use is probably a function of how much nailing depth you
    have to play with at the receiving joist - a single joist thickness
    up against a concrete wall won't take even 8d nails!
    
    

     I just finished building a deck last weekend where I hung about 18
     2"x8"x8' joists.  I filled all the hanger-to-ledger holes in the
     hangers with 16d galvanized nails; I believe there were five holes
     on each side of the hanger.  You're correct in saying that the 16d
     nails don't fit through the hole, but one good hit with the hammer
     will force it through, then you're home free - sort of.  I bought
     some hanger-joist nails to secure the joist to the hanger.  These
     were brass nails just over one inch long; I filled all these holes
     also.
     
     The joists were close enough to the ground to where I used blocks
     of wood to support the joist at the right height, then nailed the
     hangers to the ledger board.  I know another person that finished a
     deck a few weeks ago where he toe-nailed the joist to the ledger
     then secured the hanger with 16d nails.
     
     I discovered that it requires good, solid blows with the hammer
     otherwise too many blows will cause the nail to bend.
     
     The 10d nails might be enough, but I wouldn't trust the 8d nails -
     just my peace of mind.
     
     Joe

    I've used joist hangers only once and only a dozen or so.  A half-dozen
    holding joists onto a ledger board spiked into the house, and the rest
    holding joists onto ... uh ... the other side of the deck.  I used,
    I'm not sure, 8- or 10-penny nails into the ledger board, and the
    joist-hanger nails everywhere else.  I used about 2/3 of the joist-
    hanger nail holes.

    Isn't there a point where too many nails, especially large ones, too close
    to each other, weakens the wood?  Some nail holes in the hangers are
    an inch or so apart.

I know that before there WERE joist hanggers, people thought nothing of simply
toenailing joists to the ledger.  3 16d nails on each side of a 2X10 is
extremely strong.  I guess my technique sort of uses the joist hangers for
positioning the joists more than supporting it, although every bit helps.
Even if I welded the hangers into the ledger, I'm not sure if it would keep the
joist from twisting, where the toenails would certainly hold the joist in place
better.

In my case, I had to install something like 40 in one line (supporting a 50 foot
floor) and didn't want to even think about not making it strong enough.  If 
nothing else, the hangers make the job go a lot quicker than without them.

But to get back to the key point, is there a stated method for using these
things?  Is there any literature published by manufacturers?  We can specutlate
all we want, but I'd be curious to know what the engineering (gasp) is.  Did I
waste my time doing all that toenailing?  Did the person who put in all those
16d nails in the hanger waste his time?

I'm going to be putting up a second floor using joist hangers this weekend and
plan to do it the same way, but if there's a better way I'd certainly like to
hear it.

just curious...

-mark

    Joist hangers are designed to withstand  most any kind of shear
    force you could put on them. The use of 16d nails in every hole
    sounds like over doing it but if it gave you piece of mind, that's
    OK too. I'd wonder if you had split the heck out of the ledger tho?
    Whenever I had used J Hangers, I've always used 8d or roofing nails,
    three maybe four in each side is fine. I've built many decks, landings,
    platforms, etc., using J hangers any none have fall'in down yet!

remember, that in the base note I said I'm NOT doing a deck, but rather a house.
However, a deck loaded with a foot or two of snow probably weighs a hell of a 
lot more than a house full of furniture.

-mark

In planning for a hardwood floor we'll be installing soon, my wife and I were 
examining the joistwork around our new basement stairs.  The stairs were
recently rebuilt in a differently-shaped opening, so the joists form a maze
Dave Barry would be proud of:  the header that held up the joist-ends for
the old opening has itself been cut off and headed off for the new opening.

Although nothing upstairs moves or squeaks, my wife (a mechanical engineer)
decided she didn't like the looks of a couple of joints, which appeared to
be held together by a few end-driven 16d nails, apparently not supplemented
by toe-nailing.  She suggested joist hangers, and to maintain domestic 
tranquility, I ran out and bought two singles and two doubles for the job.

Only when I went to put 'em up did I discover the gotcha, although I
probably should have anticipated it.  The joists in question are old ones,
and made of FULL-DIMENSION LUMBER.  Joist hangers are made to fit modern
nominal-dimension lumber snugly, so there's no chance of just forcing them
into place on the oldies.  It's also hopeless (and probably a bad idea 
structurally) to try to chipmunk slots out of the joists - that old wood is 
TOUGH.

Maybe I'll try to re-bend the JHs, although doing so will probably reduce 
their effectiveness.  Or maybe I'll just forget it - those joists aren't
going anywhere.

    Re. .12 "Full" size lumber
    
    Why don't you buy the joist hangers one size too big and then shim
    the joists with scrap lumber to make up the difference and a nice
    tight fit.
    
    For example, if the joist is really 2" thick, buy the double joist
    hanger with a 3" wide gap. Shim the 2" joist with a couple pieces
    of 1/2" plywood on either side and now you've got a perfect fit.
    
    As far as nailing goes and the strength of the joint. I've also
    heard that joist hangers (when properly installed) are stronger
    than end nailing. For nailing, sufficiently long roofing nails,
    3 to a side into the beam your attaching to and two to side into
    the joist should do the trick. Too many nails starts to split the
    wood.
    
    Charly

I guess this is getting to be a question of structural strengh of the nails
themselves.  I know that 8d are a lot weaker than 16d.  In either case, one can
look at a chart to see what the shear strengths are.  As far as I know (which
probably ain't a whole lot), roofing nails aren't structural. They simply hold
down shingles, so before I used them in joist hangers I'd at least like to know
what size common nail they compare to.  I would think all that galvanizing
would weaken them somewhat.

-mark

RE;.12 - Joist hangers and full dimension lumber

    Try looking at some of the flat nailing plates for this situation. I 
have used nailing plates that are about 2" x 4" or maybe bigger. They are 
flat steel that have a number of perforations for nails in them. Bend each 
one into a 90 degree angle along the long side and nail them up. That 
should hold as well as your joist hangers and avoid the need to shim or 
rebend already bent hangers. Two per joist, I would think would hold up 
everything in sight. Also keeps domestic tranquility over the breakfast 
table.

    If you don't want to try bending the nailing plates, try the preformed 
angle brackets that they sell. Assuming you are not doing every joist the 
cellar, it should not be an expensive job. You might want to use dry wall 
galvanized screws to attach these angle brackets.

    I agree that the end nailing provides nothing to the joint. There is 
virtually no sheer strenth to nails, and driven end grain, they are nearly 
useless. Toenailing gets it strength from the angle of the nail and the 
opposing nail angle.

Vic    

    Be careful with the free form hangers.  Most building inspectors
    will look for a continuous band of metal down one side of the joist
    across the bottom and up the other side.  The free form where the
    bottom is formed by the right angles of the 2 side pieces bent in
    gives weak spot at the bottom of the joist - right where you want
    all the strength!
    
    I question the point about no shear strength of nails.  That's
    precisely where joist hangers get their holding power - from the
    shared shear strength of multiple nails.

>    Be careful with the free form hangers.  Most building inspectors
>    will look for a continuous band of metal down one side of the joist
>    across the bottom and up the other side.  The free form where the
>    bottom is formed by the right angles of the 2 side pieces bent in
>    gives weak spot at the bottom of the joist - right where you want
>    all the strength!
  
    	My intention with this plate was to have nothing across the bottom 
of the joist, but the two plates, one on eitherside of the joist bent to 
nail into the joist and header board. BTW, I know the job DCL is speaking 
of and the building inspector is long gone. Don't know if he ever saw the 
end nailed joists or not. All we are doing here is satisfying the 
homeowner. 
  
>    I question the point about no shear strength of nails.  That's
>    precisely where joist hangers get their holding power - from the
>    shared shear strength of multiple nails.

    	I learned what I know about joist hangers and nails from a friend 
who is a competent carpenter. His comments were that end nailing buys you 
virtually nothing until you angle the nails. Going straight into the end 
grain of a piece of wood is useless. Angling the end nails, or, better yet, 
angling in the toe nails is a far stronger joint. Also, you should angle 
your nails into the joist hanger to increase the shear strength because they 
are then working against each other. 

    Your comment of "shared shear strength of multiple nails" is exactly 
what joist hangers are all about. End nailing probably bought you 2-3 nails 
at the most into each joist. A hanger gets you 8-12 nails. You can break a 
thin branch easily, but you can't break a dozen of then together in a 
bunch. Same thing holds for nailing.

Vic

    It's not the shear strength of the NAIL that suffers when end nailing
    into a joist, it's the fact that the nail is running parallel to
    the length of the grain that sacrifices strength. By angling the
    nail, you cross many fibers of wood grain and thus gain strength.
    It's easy to separate the fibers one from the other but much more
    difficult to break the actual fibers.
    
    Dave

    Learn something new every day!
    
    I guess what you're all saying is that you should never bang a nail
    straight in.  Always angle it to some degree and its stronger. 
    Is this always true?  It sounds especially important when end nailing.
    Is it really that much stronger though?
    

    I know I'm re-opening an old note but there are a couple of things
    mentioned here that I've had experience with.
    
    1) Solid bridging may not match code. The load factor is the reason
       for using bridging, as explained earlier. The proper place for
       solid bridging is in bays (space between joists) where the span
       is =< the width of the joist. Other wise use 1x3 with 6d or 8d
       nails.  In new construction nail the tops of the bridging only,
       then install the sub-floor, then go nail the bottoms of the
       bridging.
    
    2) The best block to beat on when installing T&G plywood is another
       piece of T&G. As earlier stated beat on the groove side only.
       By using the T&G block the Tongue prevents the groove from
       distorting and making it impossible to mate the next piece.
    
    
    --------------------------------------------+
    				|		|
    			    +---+		|
    	Sub-floor	    |		Block	|<--- Beat here
    			    +---+		|
    				|		|
    --------------------------------------------+
    
    Alan

This isn't a question but some info I thought some people might be interested
in hearing.  I'm going to be removing a 19' section of 1-st floor outside wall
and need to support the opening.  There is a MAJOR load on that wall since it
has to support the second floor AND 2 roofs (to difficult to draw with primitive
graphics).

Anyhow, I had architect talk to his structural engineer and they came up with
two alternatives, the first being a steel I-Beam 6X14 and the second a laminated
beam 6X19.  The prices were $200 and $850 respectively!  The other problem is 
that even in the case of the I-Beam, I'd have to recess it into the ceiling if
I don't want to bump my head and that would be a major effort.

So, back the the structural engineer and what he came up with impressed the hell
out of me.  He essentially hade me make a wooden truss that cost a fraction of
the I-beam (when you consided the labor as well as the materials).



				|    | 
				|    | 
				|    | 
				|  +-+-+-+
				|  | | | |
				|  | | | |
				|  | | | |
				|  +-+ +-+
				|    | |
				|    | |
				|    | |
				|    | |
				+----+ |
			  	|    | |
		-------------------+-+ +-+
			 	   | | | |
		2-nd floor 	   | | | |
			 	   | | | |
		-------------------+-+-+-+

what you're looking at is a truss made out of 1/2" plywood sandwiched between
2 pairs of 2X10's.  The plywood is a full 48" wide (out of scale in this 
picture).  One inner 2X10 is the existing header of the 2-nd floor and the other
is recessed into the existing 2X4's of the 2-nd floor.  The exterior plywood is
then nailed/glued to the wall and exterior 2X10's nailed/glued to them.  The
resultant strength is then equal to the I-Beam!  This totally blew me away.

natually any project such that requires the removal of a wall is unique and
would need to be individually spec'd out, but I thought sharing this might give
others some new approaches to this problem.

btw - this now increases the width of the wall by 1-1/2" and therefore also
requires adding strapping of the same width to provide a uniform surface for
applying the sheetrock.

-mark

I'm knocking out a 20' section of wall in the back of our house to enlarge our
family room.  I've already trussed the second floor so I don't really need any
structural types beams below, but my real problem is in typing the new and the
old together.

The family room has pin beams running perpendicular to the wall.  When the wall
is removed, they'll just stop.  My plan is to put in a beams to connect the 
existing ones to.  My problem is that the current beams are stained a real dark
color.  My question, is what to do?  I figure I have a few options:

	o	paint the beams - I don't like this

	o	box in the beams - I hate to hide them

	o	bleach them - I tried some chlorox and it didn't do a thing.
		are there significantly stronger bleaches?

	o	plane/sand them - this sounds like my only practical choice if
		all else fails

	o	have I missed something?

Now, what do I do about the 20' beam?  I want to use pine and I'll need a 6X7
beam.  I could certainly get a freshly cut beam from the lumber yard, but I'm
sure it will shrink away from the plaster leaving ugly gaps.  Are theree ways
to minimize this?  Does anyone know where to get something less likely to
shrink, such as a dried pine beam? 

-mark

Ummm... One option you didn't mention - did you rule this out already? - why 
can't you stain the new beam to match the old ones?  Or do you just not like 
the dark color?

Any option other than a fresh-from-the-saw pine beam is going to run serious 
$$$.  Two options that I know of are gluelam beams and KD Douglas Fir beams - 
I'm sure either one would run you well over $500.

We built our house with pine beams, and sure enough, it has shrunk away from 
the plaster.  As we work our way around the house doing the finishing, we're 
plastering in the gaps, now that the beams are dry.  It really doesn't take 
long, and for one beam it would be a snap.  Just put in the green pine beam, 
and then in a year or two replaster the seam.  A couple of hours replastering 
will save you hundreds of dollars.

Paul

    	Most hardware stores carry wood bleaches.  I've never used them
    so can't say whether they work or not, but it wouldn't hurt to buy
    a box and give it a try.

    How about running a strip of molding along the beam/plaster interface?
    I am going to do some of this to correct some gaps around beam ends.

sounds like a green beam and replastering make the most sense...

Is there any problem with green pine twisting?  I've heard people warn about 
this.

ANy ideas of how to get rid of the dark stain in the existing beams?  I really
don't like dark dark stain.

-mark

does anyone know if 2X6 are adequate for roofrafters for a garage 24' wide
witha 11"/12" pitch (that makes 18' rafters).  I will be putting in 2x4 knee
wall supportson each rafter.

    a assume you are building this yourself!! have you considered using
    pre-fab trusses?  you lose storage space but this may not be a serious
    problem.

    
    go to your local building supply house with your dimensions and
    they will tell you exactly what you need. My guess is that you would
    need 2x8 minimum, but why guess when these folks can help you do
    it right.
    
    After all it would be a real son of a gun to wake up after a big
    snow storm and have to shovel out your garage.
    
    JMB
    

    re.0
    My 24x30 garage(same pitch) has 2x4 prefab trusses and is adequate
    for local code. BTW-Our snow load is probably less here in colorado
    than most of the east so check with your local building codes.
    
    -j
    

re .1: I need the storage space so thats a no to trusses.  The builder who is 
framing it for me said to use 2x6 but I wanted to double check. I am using
2x6 for walls (to get strength, I plan to store a lot of weight upstairs) 
so maybe I will go with 2x8.
thanx

RE: Note 2308.5 STEREO::COUTURE
    
    
>re .1: I need the storage space so thats a no to trusses.  The builder who is 
>framing it for me said to use 2x6 but I wanted to double check. I am using
>2x6 for walls (to get strength, I plan to store a lot of weight upstairs) 
>so maybe I will go with 2x8.

    ??? Do you mean 2x8 floor joists as opposed to roof rafters? 2x8
    roof rafters won't help with the upstairs weight. Or am I reading
    you wrong?
    
    Charlie

<does anyone know if 2X6 are adequate for roofrafters for a garage 24' wide
<witha 11"/12" pitch (that makes 18' rafters).  

Assuming you are using #2 SPF which is fairly common in New England and a 
40lb/sq-ft load with 2x6.

With 16" O.C. spacing the maximum horizontal span(not rafter length) is 9'8".

With 12" O.C. spacing the maximum horizontal span is 11'2".

#1 SPF 2x6 would be 10'8" and 12'4", respectively.

#2 SPF 2x8 would be 12'9" and 14'8", respectively.

#1 SPF 2x8 would be 14'1" and 16'3", respectively.

If a 30lb/sq-ft load(not recommended for N.E.) is acceptable then subtract 
about 12%.  These numbers only apply for roofs without an attached ceiling.

<I will be putting in 2x4 knee wall supportson each rafter.

You actually want to install a purlin and purlin stud wall.  If you use this 
method make sure you tie into the load bearing walls of the house.  If the 
purlin stud wall does not align with a load bearing wall the joists must be 
beefed up to handle the weight.  BTW, ceiling joists in an attic are typically
rated for 10lb/sq-ft, so if you plan on using the attic for other than light 
storage you may wish to beef up the ceiling joists anyway.   

    Check with your local building inspector.  For something as large
    as a garage, it doesn't make sense (cents) to find out after you're
    done that it won't pass code.
    
    Some towns require building prints prior to issuing a building permit.
    Others are less lenient, but still require inspection after the
    fact.
    
    Better to be safe than sorry.
    
    	Ted

re .7 
>You actually want to install a purlin and purlin stud wall.  If you use this 
>method make sure you tie into the load bearing walls of the house.  If the 
>purlin stud wall does not align with a load bearing wall the joists must be 
>beefed up to handle the weight.  BTW, ceiling joists in an attic are typically
>rated for 10lb/sq-ft, so if you plan on using the attic for other than light 
>storage you may wish to beef up the ceiling joists anyway.   

can you explain further what a purlin wall is?  I will be using 2x10 for joists.
Cant I just put 2x4 knee walls from rafter to joist to help support?

<can you explain further what a purlin wall is?  I will be using 2x10 for joists.
<Cant I just put 2x4 knee walls from rafter to joist to help support?

	A purlin wall is typically(but not necessarily) a load bearing knee 
	wall.  A purlin is a board running across the rafters on the 
	underside of the roof rafters.  Purlin studs connect the purlin to a 
	load bearing wall or joists.  Ideally, the studs should be at a right 
	angle to the pitch of the roof, but under no circumstance should any 
	angle of the triangle formed by the roof, studs, and rafter exceed 
	90 degrees.  Typically, the studs are perpendicular to the joists, 
	forming a wall.  

	If the purlin wall does not rest directly over a load bearing wall, then
	the joist must be beefed up to handle the additional weight.  The load 
	on the joist would be a point load equal to 1/4 the total load from the
	roof(in lbs/ft).  These are not easy calculations.  If you plan on doing
	this, definitely hire an engineer.

	Brian

>< Note 958.26 by AKOV04::KALINOWSKI >
>                       -< I've finally got 'THE ANSWER' >-

>    Anyways, If you are going to add an addition that costs over 10K,
>    spent a grand and get an archutect to design it for you in the first
>    place. You'll sleep better for it, and save that much along the
>    way. 
 
      For sure, For sure!  For a few hundred dollars you get:
          
          o Assurance that the structural design is sound
          
          o Elimination of a major class or possible problems with
            the building inspector
          
          o The benefit of ideas from someone who (probably) has
            wider experience than you
      
      I'm glad things worked out well for you.

    I've got a 12' x 19' room over my garage that I'm going to finish.
    One wall of the room is a 5' high built-up wood truss supporting
    the floor and roof.  I'd like to put a small door through the truss
    to have access to the space on the other side for attic storage
    (its only suitable for storage because of the sloping roof. The
    space on the other side of the truss starts 5' high, sloping down
    to 0).  The diagonal members of the truss block any doorway.
    How can I reinforce the area around a doorway to allow me to remove
    one diagonal member?  Can anyone recommend an engineer who could
    examine the problem and suggest a solution?

                                         Thanks,
                                         Bruce

	If you look closely at the the truss, the bottom probably does not 
	rest on the ceiling joists. The truss carries the load from the roof 
	out to the end walls.  You can not simply cut and reinforce trusses.
	You will probably have to replace them($$$).  You may be able to get 
	some help from the original builder or the truss manufacturer(info 
	stensiled or burned on some trusses.

	I suspect that the ceiling joists may not be strong enough to support 
	adding a second floor.  If they are 2x4 or 2x6 they definitely are not.
	If they are 2x8 or 2x10 you will have to do some additional checking.
	Is there a structural wall under the center of the floor joists?

	UNDER NO CIRCUMSTANCES should you sheath over the truss.  Build a 
	seperate wall in front of the truss.

	Brian

    The bottom of the truss definitely does not rest on the ceiling joists.
    Hanging from the bottom of the truss are two 2x8's, and the ceiling
    joists (which I think of as floor joists for the second floor) rest on
    them.  These joists are 2x8, but they are also about 24' long.  The
    definitely cannot support a second floor by themselves, but I believe
    they are transferring the load to the truss.  I believe the truss can
    support the loading of the one additional room in addition to the roof.
    There is no structural support under the floor joists. The truss is
    supported at either end by several 2x4 studs. 
    
    I was going to build a 2x4 stud wall in front of the truss for
    sheathing, for the convenience in sheetrocking and putting in
    insulation.  However, I'm curious, why is it so important?
    
    If I can't cut the truss at all, I can live with it.  The truss
    is so large that the diagonal openings are large enough to climb
    through easily.  Most stuff I'd want to put in the attic would fit
    through as well.  I'll just put in a small door in, and have to
    climb over the diagonal member to get to the attic.
    
    			Bruce

    Last night, while trying to find a leak into my cellar caused by
    the torrential rains I found what seems to be a structural defect
    in my house. The water was coming from under a slider in the kitchen
    and down the foundation wall. So I climbed on a chair to inspect
    the area and noticed that the joists and the floor are about 1/2"
    away from the joist header. I can fit my fingers through the crack
    and I can see the aluminum door sill. Could this be a structural
    problem or is it common to nail the joists away from the header?
    I couldn't see any shims, so I am inclined to believe the joist
    header has been pulling away from the house. This is on a
    three-year-old house which has been having this and other water leak    
    problems for three years. I want to run this by knowledgeable people 
    like yourselves before I go back to my attorney and finally ask him to  
    file a suit. I have been thinking about filling the gap with that  
    foam in a can stuff to try and stop the leak, but if the damage    
    could get worse I rather sue the builder even if he is my neighbor.
         
    Thanks for any advice.
                          

    Re: .20
    There shouldn't be a gap.  It sounds as though the joists are 
    pulling away.  Check a joist on either side to see if they have gaps 
    too.  If it's just the one, that's probably from sloppy work but not 
    a problem.  If it's all of 'em, I'd say that was a problem...maybe.
    A 1/2" gap does not mean your house is about to fall down, but I'd
    worry about why it is there, and is it getting any bigger.  The
    problem (if any) is why it's happening, not the gap itself.  I'm rather 
    amazed that the header can pull away (if it is) from the joists,
    because presumably your 3-year-old house has platform-frame 
    construction, and I would have expected the (presumably plywood) 
    subfloor to be nailed to the joist header as well as the joists, very
    securely tying the two together.  
    Assuming something has moved, can you figure out what it is?  Either
    the joist header has moved out, or the joists have moved back.
    Offhand, I don't see how or why either one would happen, but maybe
    it did.  Maybe the builder used really green lumber, and the joists
    shrank in length???
    Do you really need to sue your neighbor the builder???  You said
    something like "finally file a lawsuit" so is this perhaps only
    the latest in a long string of unresolved complaints?  Unless you've
    tried numerous other times without success, go talk to the guy 
    before you call in the legal beagles.

    
    
    	I'm having a little trouble understanding what joist header
    your talking about. From my impresion of the area you're talking
    about, the floor joists are on top of the sill in the basement and you
    are refering to the band joist which runs around on the ends of
    all the floor joists and there is a gap between them. Is this a
    correct ASSumption? 
    	If this is correct I wouldn't worry to much the band joist has
    very little to do with the structual integrity of the house (at
    least at the basement level). Most all the weight rests on the floor
    joists which is the transfered to the sill and down to the foundation.
    I'm sure but the primary function of the band joist is to keep the
    floor joist from twisting and rolling over onto their side. As long
    as the gap is not so big as to allow the nails to pull out of the
    ends of the floor joists you should be fine. 
    	More than likly the hous was built this way with some sloppy
    cutting some of the floor joists were cut short and they just put
    them in anyways.
    
    			Just a thought...
    
    	...Dave
    

    Re .22 - The band joist is what I refer to as the joist header.
    The symptom shows on the entire east side of the house. I haven't
    checked the opposite end, though. This is just the last development
    in a series of problems that started with the first spring rainstorms
    three years ago. The only thing that has kept me from throwing my
    lawyer at the builder (and my lawyer feels I have one of the best
    documented cases he has ever seen with pictures and all) is the
    fact that this man is a neighbor. He has made a few futile attempts
    at repairing but most of the time it has been a quick-once-over
    patch.
    
    I think you're both right. The structural integrity of the house
    should not be severely compromised by the fact that there is a half
    inch gap there. The problem will happen if the gap increases to
    the point where the nails don't have a good hold on the joists any
    longer.
    
    I'll see if I can get the courage to talk the builder into looking
    at it.

    I will be redoing the family room in my house and plan to increase
    the ceiling height by replacing the ceiling joists with scissors
    joists.  I have already looked at the code (negligible info on trusses
    there), called a truss maker (Wilson Lumber in Concord; the guy
    referred me to the building inspector), and one of the Framingham
    building inspectors (he referred me to an engineer/architect). 
    
    Well, I'm not very willing to part with $$$ for something that doesn't
    strike me as necessitating a full blown engineering analysis.  So
    I wondered if some of you folks out there could give some advice.
    Any advice is welcome and I will be forever grateful.
    
    The roof's specs are as follows:
    
    Family room = addition to the main house, which sits on a fieldstone
                  and granite foundation.  Addition sits on a slab.
    
    Roof Pitch = 8:12
    
    Length (parallel to roof ridge) = 20'
    
    Width = 22'
    
    Rafters = 2x6's 27" o.c.  for the first 12' of the length of the
                                                roof.
              2x8's 20" o.c. for the remaining 8" of the length of the
                             roof.  This section was added later and
                             is furthest away from the main house.
    
    Ceiling Joists = 2x6's 27" o.c. and 18.5' long for the first 12'.
                     2x6's 20" o.c. and same length for the other 8'.
    
    Questions:
    
    1- Should I add additional rafters to the 2x6's 27" o.c. section to
       make the roof sturdier?  (Note - there is no visible roof sag)
    
    2- What size scissors joists should I use? (I'm guessing 2x10's)
    
    3- At what points along the rafters should the scissors joists be
       attached?  (1/3 of the way down?)
                   
    Alfonso

    I need to reopen this note, with some related questions.
    
    Our architect did a roof design for our garage addition that shows no
    extra supports in the attic -- just rafters and ceiling joists.  The
    joists are spec'd at 2 by 8 spruce.  I've forgotten the rafter spec,
    but I think they're at least 2 by 8 as well.  I don't think there are
    posts holding up the ends of the ridge.  Since it's a cape with a
    dormer out the back (10/12 and 4 5/8 / 12), the joists will intersect
    the front rafters somewhere in the middle (about 5 feet up), but
    they'll hit the back rafters at about the end of the rafters.  The
    total span of the ceiling joists is about 19 feet.  The design also
    shows a post in the center, over the first floor beam.  Since the post
    will be inside a wall, it will be supporting the top plate, and
    indirectly supporting the ceiling joists. The architect did say that if
    we went with 2 by 10 ceiling joists, we could do without the post
    altogether. We've considered doing this, since that would give us the
    flexibility to postpone and reposition the wall around when we finish
    the upstairs at a later date. 
    
    The builder we spoke with last night seemed pretty insistant upon
    not only putting in the second floor wall, but also also putting
    in the king stud arrangement, as described earlier in this note.
    That is, running boards vertically from the ridge to each ceiling
    joist.  His concern was that the walls would be forced out;
    the studs and second floor wall would bear some of the weight,
    relieving the outward force on the wall.
    
    From what I can tell compared to other specs, the architect's design
    seems fine.  Two by tens ought to be sufficient for an unfinished
    attic, even over a 19' span.  I might be tempted to put in collar ties
    ties to hold in the rear wall, but I don't see that the king studs are
    necessary.  Of course, they're only money.  My real goal is to be
    able to postpone positioning the second floor wall as long as possible.
    
       Gary
    
    The real frustrating part is that the architect and builder have
    worked together in the past, so you would think this sort of design
    would have come up previously.  At least, I'm surprised the builder
    didn't just trust the architect, which makes me wonder whom to trust.

    Can't find any explicite questions, but seems to me there is an
    implicit question which I read to be:
    "Who should I trust my builder or my architect?"
    Answer: This is a question for a building engineer.

Can anyone recommend the best way for me to estimate the size of beams,
rafters etc. needed for a given load?  Right now I want to know what size
beam I'd need to support 1000lbs max from its center and span a span of 14'.
I want to put a chain hoist in a garage.

-Mike

    Assuming you are intending to use the chain hoise for pulling
    car engines, you might consider using steel I-beam.  This would
    allow you to use an I-beam trolley with your chain-hoist.  This
    would allow you to better position the hoist over the target engine
    and also give you the ability to easily move the engine around the
    shop (in a straight line).

Actually I already have a trolley and a short (8') piece of track it runs on
that I was planning on using.  I was actually intending on mounting this, rather
than the chain hoist itself, to the beam (actually 2 beams, one at each end)
Like many other people, I need to save a few $$$, and a couple wooden beams
and using the track and trolley I have is less $$$ than a new steel I-beam, if
I can get away with it.

-Mike

    While I can't give you an exact answer,  I  made  overhead shelves from
    plywood and 2*6 on a 12 foot span, they  probably  support  300  lbs  a
    rafter easily but they deflect more than I'd feel comfortable  with for
    a hoist.
        
    I use a pair of 2*12's to span 12 feet in my garage for my hoist.  I've
    used it for engines and as a safety when I have a  car on stands.  I've
    never  seen  it deflect at all.  The reason I used two is  so  I  could
    clamp  around the roof beams to make sure the planks couldn't twist and
    fall on  their  flat  faces.  When you attach your steel beam make sure
    that sideways forces  (which you will be exerting) on the wood supports
    won't topple them.
    
    If I was to do it again I'd use a pair of 2*10's and save a few bucks.
    
    George Dvorak

    This is not a typical house framing loading situation.  You have
    a 1000 lb POINT load in the middle of a joist.

Mike,

You must  plan  for  1Klbs  at the center (worst case loading) of the 14' span.
According to "Marks",  that  means  you  can  get  away  with  using two 2x10's
(nominal measurement) and meet minimum safety.

However, if you are  of  the  nervous  bent (should be if you will be UNDER the
beam) you will realize that not all woods are the same, nor do they exhibit the
same characteristics the day they are  cut  as  they  do 5 years later and much
dryer.  You might prefer a safety margin.  Go for two 2x12s which would yield a
safety margin of about 50%. 

Luck,
Dave

OK, looks like quality 2x10s or 2x12s.  But to complicate matters, what if I
tie into the roof rafters (2x6s) and form sort of a truss?

What is this "Marks", a book?  It probably has all my answers.

-Mike

>What is this "Marks", a book?  It probably has all my answers.

"Marks' Standard Handbook for Mechanical Engineers", McGraw Hill

An incredible resource, it covers more subjects than you ever will care about.
Additionally, much of  what  it presents is sufficiently footnoted to point you
to even more detailed sources.

It is also big enough to be used as a sea anchor.

Dave                

    One other idea to try, is your local town hall (or wherever building
    permits are issued in your town).  When we got our first permits, they
    gave us a few handbooks, and there were a lot of 'per foot', per
    pound', per person', type of things in it.  Also my husband talked to
    the building inspector, and got a lot of info from him.  These people
    eat, breathe and sleep this stuff -- you'll probably get your exact
    answer for your exact application in a few moments. (this is NH.)
    
    		

Here's the problem (or opportunity):
The loft in my townhouse was roughed in to be finished. The drawing below is
definately not to scale but there really is a lot of room up there. The
problem is that the existing skylight would light none of the room unless I
treated it like a dormer-not very practical to me.  I expect this existing
configuration could be called a truss, especially since it's 2'oc. and uses
those metal plates for nailing the components together. Although the diagram
might be misleading- the skylight is at a reasonable height so raising it
higher in the roof would not be a help.

What's there now:                       |
                                       / \
                                      /   \
                                     /-----\
                                   //|     |\
                                  // |     | \
                    skylight---->//  |     |  \
                                //\  |     |  /\
                                /  \ |     | /  \
                2x4 braces-----/--->\|     |/    \
                               ------|-----|------
Rafters are 2x6 and small braces are in place in joint in rafters

I'd also like to get rid of a couple of braces on the other side to free
up room for a closet.


What's desired
                                        |
                                       / \
                                      /   \
                                     /-----\
                                   //      |\
                                  //       | \
                    skylight---->//        |  \
                                //         |  /\
                                /|         | /  \
                 Knee wall-----/>|         |/    \
                               --|---------|------
Someone has suggested just doubling up the rafters, put in the knee wall,  and 
then removing the small braces .

Will this work?

Ad-thanks-vance
Ray.
 

	Has anyone had any experience with a product that I believe is
	called "Silent Floor?"  In the Atlanta area, several builders
	are using this for their floor beams.  It appears to be a pair
	of 1x1's connected to a piece of 1/4 inch plywood.  In cross
	section, it looks something like:

		+------+
		|      |   <-------1x1's
		|  ++  |
		+--||--+
		   ||
		   ||
		   || <------------1/4 inch plywood
		   ||
		   ||
		   ||
		   ||
		   ||
		   ||
		+--||--+
		|  ++  |
		|      |
		+------+

	This is being used in place of 2x10's or whatever the size is on
	most houses.    Anybody have any opinions, experience with this
	stuff?  I'm concerned about how well it will hold up over time...

	Thanks,

		Rick Beldin

    I just finished a 24X26 master bedroom over my garage and didn't want
    to split my garage into two bays by adding columns/etc.. My carpenter
    put in PJ's Silent floors. They make all lengths and heights to span
    just about any area...The dimensions for mine were 24'X14"..
    
    1.) They're guaranteed by the manufacturer
    
    2.) Inexpensive
    
    3.) Supposedly won't warp because like plywood,they've been
    glued/pressed/glued/pressed/...you get the picture.
    
    If they won't warp..supposedly your floor won't squeak because no
    warpage means no nails rubbing(casuing the squeak)...
    
    I would recomment them use them again if needed...
    
    
    
    							john

    One more thing...they are cheaper then adding I-beams...
    
    A crane would have cost me 1500+
    
    
    						john

    When I was house hunting here in Colorado, we were shown houses
    which have the "silent floor". I did not like the way they bounced
    when you walked across the floor. You didn't even have to be a real
    "heavy walker"... the lightest walk would shake the entire room.
    One place we went into.... the owners had their glass items on rubber
    mats to keep them from shaking off the hutch when they walked by.
    
    Now, I still have an open mind about the concept. IF the product
    is made properly, and construction contracters utilize the highest
    quality product, then I see a benefit. 
    
    In the example above, I'm sure the house was built with "a new concept
    product" and no one really knew how the product would perform in
    a real life situation.
    
    I'm sure that in time, they will have fixed the "bounce" problem
    and perfect the product. For now however, I would probably want
    to closely look at the quality prior to having it installed in
    something I was having built.
    
    I think the thickness of the vertical piece (plywood) should become 
    thicker as the beam itself gets deeper (between 2x's). In the house
    I have seen, there was a single 3/4" piece of plywood between two
    2x4s approximately 16" apart. I think there should have been two
    pieces of 3/4" ply and about 12" between 2x's.
    
    My opinion..!

    One other thing I had forgotten about......
    
    If you are building a "master bedroom" and are planning to have
    a waterbed in that bedroom... BE REAL SURE to state that at the
    planning stages (with the contractor) to insure the "silent floor"
    is strong enough to handle the waterbed.
    
    JUST A SUGGESTION..!

    	.3 is in error as to the improvements needed to make the beam more
    stiff.  In a rectangular beam, almost all of the stiffness comes from
    the elements at the extream ends of the beam cross section. That's why
    I-beams work.  The web between the end plates just keeps the plates
    from moving relative to each other.  To increase the stiffness of the
    plywood beam (assuming the web isn't warping) you need to either:
    	1. Increase the distance between the end plates, or
    	2. Increase the cross sectional area of the end plates.
    Basicly, you want to increase the cross sectional moment of inertia of
    the beam. It's a large function of the distance between the end
    elements (either ^3 or ^4, I forget), so a 12" deep beam is a LOT
    stiffer than a 10" beam and so on.  - Chris

    There's a new house being built in my town that is using the SF
    system. I happened to walk through it during the construction phases.
    I was not impressed with this system. The house appears to be a
    reverse saltbox, utilizing this plywood system for the floor joist.
    The floor was very bouncie. The SF joist were 24" on center and
    they used particle T&G, 3/4" subfloors. My first impression is this
    guy must be cutting corners. My general feeling about what higher
    quality construction uses for materials is good grades of plywood
    and good old 2 x 6,8,10 & 12"s. I would not feel comfortable with
    purchasing  a home that was built with the SF joist systems, but
    this is just my own personal opinion and don't mean to offend anyone
    who feels the SF systems is a good alternative to standard, solid
    material joists.

    Any floor that can handle a piano can handle a waterbed.
    
    Would you "warn" a contractor that a room might have a piano in it?

    I would warn of a piano if I knew about them... BUT I don't.! I
    did and do know of waterbeds.
    
    I do not feel that the silent floor system (the one I looked at)
    would hold a full/queen/king waterbed without the floor sagging
    or other problems occuring (over time).
    

    re .6
    I bet the bounciness is caused moreso by the joist spacing and subfloor
    material than the joists themselves. In other words, if 2x10, say,
    joists were put in place of the of SF joists, and everything else
    was equal, you'd feel the same bounciness, if not more.
    
    John

    I just built my house using TJI (Truss Joist) "I-beam" floor joists.
    Just a few of my observations.  We used 11-7/8" deep joists.  According
    to the TJI literature, these were good for 24" O.C. spacing for our
    longest span (~17').  I was worried about bouncing, so I spaced them
    at 19.2" O.C. (yes that's a standard TJI spacing).  My floor still
    bounces even when a dog walks accross the floor.  We have 3/4" T-G
    OSB subfloor, glued and nailed to the joists, with carpet on top of
    that.  
    
    A friend of mine has TJIs in his house and had the same problem.  By
    nailing a couple 1x4's perpendicular to the joists, he was able to 
    greatly reduce the bouncing.  Apparently, the joists deflect side-
    to-side and the 1x4's stop this motion.  I plan to do this before I
    finish the basement.
    
    My other observation is regarding the "Silent Floor" claim.  They
    are fine where the joists cross over and bear on a beam or bearing
    wall, but squeak where they are supported by joist hangers.  We
    used the approved Simpson brand hangers, specially sized for TJIs, but
    they seem to have enough slop to allow the joist to wiggle around
    and cause squeaking.
    
    As an aside, the TJI floor system cost ~$1000 more than a comparable
    2x12 floor.
    
    Gary
    

    My neighbor used them for a deck since the span was longer than
    dimension beams would handle (he is using the area underneath for
    a 2 car carport).
    
    I did notice some 'bounce' when I walked on his deck, but the
    contractor claimed that they were stronger for the length needed.
    
    	-Barry-
    

My builder used them for my garage ceiling, 25' span x 30' wide.  They were
used to eliminate the use of a carrier and the use of posts.  This makes for
a very clean, as in open, garage.  The loft above that ceiling has full head
room with 3/4 cdx decking.  There is no appreciable bounce when walking, I've
not tried jumping around though.  The builder put them in 12"o.c., his choice
and used the reminate ends for solid bridging every ~8'.  He's known to have
very short arms and very deep pockets.  He claims it was more cost effective
than standard stick framing to achieve the postless garage.  It may not be
for everyone but, it sure fits the bill in this application.

Frank

    To respond to several replies...
    
    I used the TJI SF because I also did not want to have to put in a steel
    I-beam and carrier posts as mentioned earlier..My master bedroom is
    24'X26'. This includes a walk in closet and a bath w/whirlpool tub for
    2 and an oversized walk-in shower...
    
    The joists are 14' wide and 23+' long..He tied them into the top plates
    without using any hangers. He put themn 16" OC and then glued down 3/4"
    T/G plywood. There is also 3/4" white oak flooring on top of that..
    
    There is NO BOUNCE in my flooring..Yea if I stand in the middle and
    jump up and down, nik-naks on my wife's dresser rattle a little..
    
    The only "complaint" is I can hear the noise of the garage door opener
    below when it's running. There is 8" R25 attic blanket along with 5/8"
    fireboard installed. I haven't plastered yet..Would the chain rattle
    opening/closing the door go away if say I had used 2X??...I doubt it..
    
    As I stated in earlier note..I'd use them again...
    
    Another "selling point"..They all have "predrilled" knockouts every
    so many inches for wires/pipes/etc.. You just take a hammer and knock
    them out wherever needed.
    
    One last comment...We also have a king size waterbed in the room.
    
    
    								john
    		

Regarding all the bounce. I can't say that I have ever used these beams, but,
even if I did I would:

	-  Not space more than 16" on center (the plywood would sage and
	   bounce between joists)

	-  Ensure at least 1" of floor (subfloor plus top)

	-  Crossbridge between joist at every 5' if spaan is more than 10'
	   (bridging causes the load to be spread to the remaining joists)

	   This is true of my outside deck. I built this without the bridging
	   and it bounces.

If I didn't do all the above things, I would expect bouncing of the floor.


	Doesn't the Silent Joint system recommend this?


	Bill

    Yes, the "silent floor system" does call for the items you point
    out. However, the construction I witnessed here in Colorado did
    not involve any of that. It seemed the contractors had made up their
    own code (there is no written code for silent floor systems yet).
    
    They were greater than 16" on center. They were not being bridged.
    So, YES, if constructed properly (even using current codes) the
    system would probably be a good one. It is like anything else though,
    If there is a way for the builder (some) to circumvent the code
    to save $$$$ they probibly will find it.
    
    My opinion
     

re.13  Please excuse this off the base note... check your door-opener manual
the chain may be improperly tentioned or aligned.  My chains have a little
slack and don't rattle.

I was in the loft of the garage last night and jumped a little.  There's very
little bounce  :-).  I operated the door openers with the remote while up there
and could hear the door operators, not too bad though :-).  When fire-rocking
the garage a couple of friends (thanks) helped me stuff 9" of insulation
between the joists, (works great).   BIG :-)

Frank

    regarding the SF owner who put down Oak flooring over it. 
    
    I had a small amount of bounce in my family room floor. Then I put
    in Oak floor. The bounce was reduced drastically - to almost nill.
    The oak helps in that it is pretty stiff, espcially nailed into
    every joist...
    
    bld

    re .14
    
    The TJI literature specifically states that cross-bridging
    is not required.  However, I think it is a good idea and
    they'd have more satisfied customers if they would require
    it.
    
    Gary
    

    I had something similar put in recently spanning 26 ft. I used trusses.
    Instead of I beam shape it has a lot of triangle on where the I
    is. The deep of the I is 18". When the carpenter first put it in
    it bounces. However, after the cross bridges where put it it became
    very stiff, comparable to other areas that didn't use the truss.
    By the way the drawing provided by the truss manufacturer does
    recommend bridging every 10 ft. As I look up at the ceiling of the
    manufacturing floor here at work the roof truss are similar except
    it is made out of steel. I also had cross bridges.
    

    The concept sounds interesting, but I'm having trouble picturing these
    beams - probably because different noters have given so many different
    specs/descriptions. Where can I find out more?
    
    The reason I'm asking is because mu older home has floors that need
    strengthening. I had decided to scarf 2X10s onto the existing joists,
    but have been putting it off because the job would be very heavy
    work. Do you think it would be possible to use these new beams for
    this type of work?
    
    Also, one person mentioned that his floor cost *more* than one with
    traditional joists. Since the materials would presumably be cheaper,
    I guess you're paying for the concept. Would it be possible to glue
    up your own?

    The idea is very interesting, I have not seen this type of beam
    in the UK but I would be very grateful if someone could find a
    supplier in the states who could send me more info.
    
    Just give me the address and I will do the rest.
    
    Many thanks,
    
    Richard Finlay.	(DecResitent in North East England)

re:  Note 3571.18 by GENRAL::CLAUSON 
    
>    The TJI literature specifically states that cross-bridging
>    is not required. ...

      Thats one of the more absurd things I've ever heard. 
      
      The  purpose  of cross-bridging is to allow the load to be carried
      across all the beams.  Without it each individual beam would  have
      to  be  heavy  enough  to  carry the largest potential point load.
      Joists aren't sized that way.  They are sized based on point loads
      being shared among several adjacent joists.
      
      Whether  using 2 by x, steel, truss of these "silent floor" joists
      you NEED bridging.

    Am I missing something?
    
    The purpose of bridging (either with diagonal straps or full size
    blocks) is to prevent the load from twisting the joists.  Very long
    and wide ( >2x8 )joists secured only at each end (the normal case)
    have enough torsional instability that this is in fact a threat.
    (If you don't believe it, try nailing something to the bottom end
    of the middle of an unbridged long 2x10/12 joist - there's so much
    spring the nail won't go in easily ! )
    
    However, all you need is just a bit of force to hold the joists
    square to the subfloor - that's why bridging is often thin elcheapo
    metal braces.

                    <<< Note 3571.20 by TLE::THORSTENSEN >>>

>    Since the materials would presumably be cheaper,
>    I guess you're paying for the concept. Would it be possible to glue
>    up your own?

A few years ago I helped a friend build his summer home in NH. About 22 of 
us showed up for a Sat barn raising. The prior week, a concrete block 
foundation had been built and a plywood subfloor constructed over the 
crawlspace. On top of that flat deck, the owner had built 35 26' or 28' 
roof trusses with a 12/12 vertical pitch. (45 degrees). Each truss 
was constructed of 2x6 lumber with 1/2" plywood triangular nailing plates 
where they ere needed on each joint. Each plate was "slathered" with white 
glue and dry wall screwed into place. The screws were just cheap clamps 
that didn't need to be removed later. When dry, the trusses were 300+ lbs 
each, but absolutely stiff and strong. I think they were overkill with the 
plywood nailing plates and glue, but the cost was small compared to 
pre-built trusses, probably much stronger due to the stiffness of the 
joints, and required only simple manual labor to construct over a pattern 
drawn on the plywood sub-floor. If you can make trusses this way, you can 
certainly make these floor joists yourself. I would use a sandwich of 
several sheets of plywood with top and bottom runners of 1 x 4's to add 
strength to the shape. you ought to get away with 1 x stock of you 
use plenty of white glue and drywall screws to assemble them. the plywood 
would need to have joints offset, plenty of glue in the sandwich, and a 
couple of days drying time, but I think you could do this yourself with a 
large $$$ savings but plenty of owner sweat equity. (a la TOH early shows)

If in doubt, talk to your building inspector for his ideas, and you will 
need a certificate from a structural engineer for the building inspector in 
all likelyhood, at least in Mass. 

I saw some of these fabricated joists 12 years ago working with a building 
inspector, so they aren't all that new, just unusual. My idea of how to 
sandwich the stock would have the plywood full depth of the joist with the 
1x stock screwed/glued onto the edges for stiffness. And I would put cross 
braces every 6-8' for added strength.Those cross braces really make a 
difference with how much bounce the floor has, and take care of some 
squeaks as well.

    | | | | |
    | | | | | <------1 x 4 pine, glued and screwed to plywood
      | | | 
      | | | <------- 3/4 cdx ply, two layers glues and screwed together
      | | | 
      | | |
    | | | | | <-------1 x 4 pine again.....
    | | | | | 

    	Vic H

    Question on rafters/joists versus manufactured trusses:
    
    What is the cost differential on these?  For example, on a 28x40
    house, would the difference between rafters/joists and trusses
    be anything more than a few hundred dollars?

     
    this looks like my best bet for the position of my question..
    

 project - multi-year old 30 x 50 (approx) cape, unfinished attic / basement.
    (by multi-year I mean.. bedroom built in 50's, kitchen in the 30's, etc).
 Problem - last year I installed two recess light in the entry way.. on
 my way back thru the attic, I slipped on one of the "joists" and stuck
 my foot thru the hallway ceiling (nice going eh...?). Well in any case,
 I have to repair the ceiling.  I'm going to tear down the plaster(?) that's
 currently there and replace with sheetrock.  Problem is - the "joists"
 as they are called are only rough cut 2x3's with 1x4's (I think) nailed
 perpendicular across the 2x3's.  No slats for the plaster (If indeed it
 is plaster).   What I'd like to do is, screw some 2x6's (will this be
 enough?) to the current 2x3's prior to repairing the hallway ceiling.
 With the 2x3's in place, can I butt ends for the 2x6's and still have 
 reasonable strength..?   these 2x3's are, I might add, 24" oc.  I'm
 kind of surprized that the attic is still where it is and not sagging
 down to the first floor (living level).   If the butted ends are not
 going to be strong enough on the 2x6's with the support of the 2x3's,
 will a 6' piece of 2x4 (3' coverage on each of the abutted 2x6's) be
 adequate..?  overkill..?   there are no plans for us to finish the 
 attic, however, one never knows if the next residents will (when ever
 or if ever that happens).    With a 30 foot span, will 3 ten footers
 abutted be ok.. ?  should I spend the extra $$ and go with 16 footers
 and lop off a foot..?   Help / advice is muchly appreciated. 
 
 Keith

    
    Figured a (poor) picture might help :
    
    
    
                      attic area.. 
    
                            |
    current 2x3's  ---->   ||  <-- 2x6 screwed to 2x3. 
                          ------    <-- 1x4's
                         ---------   <-- plaster / ceiling mat'l

I have a question.  I am in the process of replacing an existing beam with 
a laminated beam.  The existing beam was put in with sagging floor joists.
The beam was placed against the lowest joists and the others were just
shimmed.

I am planning on putting the new beam in by brining everything to the same
position (no shims).  I would like to make the job as simple as possible.
Can someone tell me where I might rent a couple of jacks?  I am assuming
that I could get away with 3 (maybe 4).  I am talking about the equivalent
of lally columns but adjustable.

What I am planning on doing is placing one at each end of the beam, and
either 1 or two towards the center.  I am then planning on cranking these
up until I have gotten the floor joists high enough to put the new beam
in place.

When we did the other side of the house, we did it the "hard" way.  We
put one end of the new beam on it's post, and then literally forced the 
other end in place (with sledge hammer and brute force, as well as a
bottle jack, and 3 guys).  I want this one to be less trouble, but planning
ahead.

So, what kind of jacks should I use?  Would the adjustable lally columns
work?  What kind of support do I have to put underneath them?  This is 
in the kitchen, raising the second floor floor joists.

I am thinking that I can just put a 2x8 under the column, across 2 or 3
floor joists (would I be better off putting a 4x4 instead?).  I was
a little unsure what I wanted to use on top.  I have been thinking that
if I put 2 2x10s together, I could put them in place and just crank up the
floor until I get high enough to put in the new beam.

Silly question.  Why can't I do this with the new beam?  As long as I put 
a piece of plywood over the top of the jack, so as not to mar the new beam,
I would think I could just put the one end on the post, and lift the other
end as high as I could.  Then, the jack could do the lifting to the remaining
height.  When I get high enough, I could then put the post under the end and
just lower the jack.

Thoughts?

Ed..

    Adjustable lally columns are NOT intended for jacking; the screw
    threads won't hold up to the stress.

    Re: .1
    
    But, they worked for me when I had to jack up my post and beam house.
    
    Maybe we differ on what "jacking" means. These adjustable lally columns
    are used to slowly push back/up beams that have sagged. I.E. one turn
    a week type activity.
    
    I used them for awhile, till I had everything where it should be. Then
    I used substituted standard lally columns.
    
    Marc H.

I would be doing the adjustments in one evening - although very small.
Just enough to get the new beam in place - maybe 5-6 inches (just a
guess).  If these are not appropriate, what is?  What do the pros use
to jack up houses?

Would a 2 ton floor jack with a 4x4 work?  It is not as stable as the
adjustable columns.  With all of the work done like this, I am sure there
is a tool somewhere.  Where is Tim Allen when you need him?  More Power!!
:^)

Ed..

    re: .2
    Yep, they work...but they aren't supposed to be used that way.  One
    is supposed to jack up the beam with a "real" jack, then adjust the
    screw on the lally column under it and let the beam down.  Not that
    people, including me, don't use them for jacking things up....
    
    When jacking, by the way, a hydraulic jack is great for lifting, but
    you shouldn't leave a load on one for any length of time; it will
    most likely leak and slowly go down.  If you need to jack something
    up and leave it jacked up for a while, you can do the heavy lifting with
    a hydraulic, then replace it with a screw jack (or adjustable lally
    column!) to hold the work in position.

    If you do things the allegedly "right" way (don't use the lally
    columns as jacks), you will probably have a short jack and a
    long post on top of it to get enough "reach" to do the jacking.
    This can be really treacherous, if things aren't *exactly* in
    line.  Having such a setup buckle and kick out, with a couple
    thousand or more pounds sitting on top of it, gets exciting.
    All in all, I'd be tempted to use adjustable lally columns as
    jacks and to hell with what "they" say...much less danger of
    accident.  Perhaps use a supplemental jack to help with lifting,
    but keep lots of pressure on the adjustable lally column too.
    

    Re: .5
    
    Exactly...
    
    Marc H.

re .3:

>I would be doing the adjustments in one evening - although very small.
>Just enough to get the new beam in place - maybe 5-6 inches (just a
>guess).

You think 5-6 inches is very small?  I've heard of the one-turn-a-week
method of using adjustable columns, but 5-6 inches in one evening strikes
me as requiring a whole different tool.

When we put the beams in on the other side, we used a sledgehammer and
LONG 2x4 to litterally force the beam up.  We put the post under it and
hammerred the post up under the beam.  This was not the proper way, but
at the time (1:00 in the morning by this point), we had no choice.

One point.  I am leaving the existing beam in place and will be placing
this beside it.  This way, if anything happens, I will not have the whole
house fall on my head.  I think I will look into the adjustable lally
columns.  I will try using a hydraulic floor jack and 4x4 to raise the
floor joists and put the column in place.  This should get me high enough
to be able to put the beam in place.

If anyone comes up with a better idea, let me know.  We won't be doing this
until after Labor Day weekend (we are going away that weekend).

Ed..

    A 4x4 may be a little weak depending on what your lifting.
    I just lifted the center beam in my house about 1/4 to 1/2 inch and
    replaced one lally colume with 2...
    
    At first we used a 6 ton hydralic jack with one of those adjustable
    pipe lally columes without the screw piece on top... just put a metal
    plate... Well the middle where there is a pin to adjust the height
    compressed over the pin... We even used  the 6 ton and another 2 or
    4 ton at the same time to go a half inch... (Two story duplex, with 
    a water bed on the second floor) GO slow and make sure it's level.
    We used an old cement lally colume later with just the 6 ton jack
    to do the end 1/2 inch... Still need a good level base or it'll
    buckel.... (Level the post) You can use the adjustable lally as a
    safety, set it in palce, jack with the hydralic and crank the adjs...

  Find yourself some house jacks to do this job. Anything else is dangerous.
House jacks are conical in shape and weigh a 'ton' thus making them less
likely to kick out under load. They are screwed to raise and lower the load.

  And I'll 2nd/3rd the previous comment about trying to take out 5-6" in one
day - you're asking for trouble.

  Patrick

I wanted to give a final update on this project (or part of a project).
We did finally get the beam up.  What we did was to rent one house
jack.  We had a friend come over.  I already had the beam and posts cut
to size before they showed up.

We put the beam up, and got it high enough to put the first post in place.
This was difficult.  But, once done, we were able to use the house
jack to jack up the other end and get the other post in place.  There
was one glitch.  We had to put the post on one side in a hollow created
by the floor, so we had to jack up the beam higher than it was going
to end up.  This was somewhat difficult as we did not have a pipe to
use for a post.  So, I nailed two 2x4s together and then nailed another
2x4 on the other end.  This stopped the 2x4s from being able to bow in
any direction.  We then just worked our way down the beam.

The total deflection (or sag) that was corrected was about 1/2 inch.  
Shows how bad I am at estimating without measuring.  Also, I had to take
an extra 1/2 inch off the length of the beam.  The length I cut was
fine except that it was too snug a fit and left no room for maneuvering.

If I had to do this over, I would rent two house jacks, and try to have
some kind of piece of steel for the temporary jacking posts.

Thanks for the help.

Ed..

    	My wife and I were sitting around last night fantasizing about what
    we would want in the house we are going to build when our lottery number 
    hits.  One of the things we both want are full 8 ft ceilings.  Which
    brought up a question.  Framing lumber comes in 8 ft lengths, sheetrock
    comes in 8 ft. lengths, EVERYTHING comes in 8 ft lengths.  Why then are
    most of the walls I've seen 7'6"?
    
    George

    RE: .24
    
    Consider the sole and top plate dimensions. Then add the fact that the
    joists for the second story sit on top of the top plates.
    
    Marc H.

    Sheetrock longer than 8' is common.  If you are of the school that
    installs sheetrock long side up, your problem is solved with the longer
    pieces.  If you are of the school that installs sheetrock short side
    up, you have minor problem in that you will have a lot of waste since
    you always want to butt beveled edges.
    
    If you are a contractor building a house on speculation, 8' ceilings
    will add to the cost of the house in both time and materials;  you may
    or may not feel the costs are recoverable.  If you are building your
    own house, the incremental costs of 8' ceilings will be lost in the
    noise of other overruns. :-)
    
    Dave

    RE: .27
    
    Amen!
    
    Marc H.

Forgive me if this has been asked before...

I'm in the process of having a new home built.  My choice on the floor
joists are

1st floor 2 by 12 24" OC
2nd floor 2 by 10 24" OC

or

1st floor 2 by 10 16" OC
2nd floor 2 by  8 16" OC

All with 1 by 3 straping.  The wall studs will line up with the joists.
16 OC is quite a bit more $$$.  Using 24 OC,  I'm not concerned with
weight, but I have concerns with the floor bowing between joists.  Rooms
with hardwood floors will stay firm and it's not noticible where 
carpeted, but I've heard it can be quite noticible where there's 
linoleum.  

Any insight or opinions?

bill

    
    	I would definitely go with the 16 inch on center joists; how much
    	more could it be? You'd be getting smaller boards but more of them.
    	The reason that I'd go for the tighter spacing is stability and
    	less bowing and squeaking.
    
    	This is one of the things that you cannot change once the house 
    	has been built. What state is this? I thought that the code in 
    	some states requires 16" floor joists.
    
    	John

    
    
    
    You might want to check with local code.  I dont think most places
    allow 24oc for FJ's....
    
    

>The wall studs will line up with the joists.

	Is this true even if you go with 24"OC? I would definitely not go
	with 24" OC wall studs.

	Roy

    Since this is all opinion anyway....
    
    If I were building a house, I'd probably go with 2x6" wall studs,
    24" oc.  (If you figure it out, 2x6 on 24" centers is exactly the
    same amount of wood as 2x4 studs on 16" centers).  I'd go with the
    2x6 studs on 24" centers to give more space for insulation, and
    fewer breaks in the insulation (a break for a stud every 24" vs.
    a break for a stud every 16").  Whatever you do on the wall, it will
    be WAY stronger than it needs to be to support the loads applied.
    Many, many time stronger than it needs to be.  So don't even bother
    to think about that.
    
    I would probably go with floor joists 16" oc to provide more uniform
    support for the floor.  Typical floor design load is for 40 lbs/ft2.
    One can achieve that with any number of combinations of joist spacing
    and size, so a floor can be made "strong enough" with 16" spacing, or
    24" spacing, or 12" spacing, or whatever you want, depending on the
    size joists you use.  But, as mentioned, if the joists get spread out
    too far one starts to get ripples in the floor if the floorboards
    aren't stiff enough, and bounce between the joists.  So I'd go with
    16" spacing.  I might be inclined to build for a design load of 
    50 lbs/ft2, just so the floor feels SOLID.  The incremental cost
    should not be all that much (use 2x12s instead of 2x10s, or whatever).
    As somebody else mentioned, you get only one chance to do this, so
    do it right the first time.

    My old house has 4X4 studs on 24 inch spacing. The floor feels somewhat
    springly...but...hey! Its an old house.
    
    The spacing formulas/rules are mainly to have the floor feel solid,
    like .4 stated. 
    
    Me? On a new house, use 16 inch spacing...maybe you want to have
    a slate or tile floor someday and *any* movement would be a problem.
    
    Marc H.

re: all 

current state:  The house style and floor plan done.  Purchace & sale is 
		signed.  I have bank commitment.  Land is not yet cleared.

The price difference is $6200.  This is for doing just tha main part of 
the house 16" OC.  The Garage and family room would stay 24" OC.  There's 
only linoleum in the main house area.

	+----------------------------------------------------+
  ^	|		|			   |	     |
  |	| 2 car garage	|	main house	   |  Family |
 28'	|		|			   |  room   |
  |	|		|			   |	     |
  v	|		|			   |	     |
	|		|			   |	     |
	+---------------+			   +---------|
	  <- 24' ->	|			   | <- 14' ->
			+--------------------------+
				<- 36' ->

The arguement for staying 24" OC is that there is less heat loss.
Wall studs are a conductor of heat loss.  Also $$$.

The builder wants to keep the wall studs lined up with the floor joists.
so switching affects both.

I'm pretty sure local code allows 24" OC although I'll double check that.

I talked to the builder last night.  Another alternative is to double
up the floor joists where there is linoleum and creamic tile so that you'd
actually have 12" OC in those areas and leave the rest 24" OC.  The
walls would then stay 24" OC.  He's getting a price on that now.

-----------------------------------
re .3

>>The wall studs will line up with the joists.

>        Is this true even if you go with 24"OC? I would definitely not go
>        with 24" OC wall studs.

Why?
-----------------------------------

FWIW: My brother-in-law (a former builder) says go with 16" OC because
of bowing and squeeking.  My brother also agrees with him.  Although
neither has heard the latest "double up" sceme.

Thanks for the responses so far...

bill

I forgot...

Yes, it will be 2X6" wall studs.

When I built my last house (mid 70's) I used floor trusses on 24" centers
that spaned 28' (no beam or posts in the center of my basement).  This was
covered with 3/4" tongue and groove plywood that was glued to the trusses.

The floor was very ridgid and I had no problems with the slate floor in
then entrance hall (laid right on the plywood subfloor with adhesive) during
the 4 years I lived there.

Not having a beam  in the 2000 sq ft basement makes for a very impressive
room.  This was a walkout basement on two sides, so it was a very livable
area.

I would have no problems with doing a similiar thing again.

Tom

PS  The building codes I have seen state that a flooring system must
be designed to hold a certain live load (50 # per sq ft) plus a dead load
(varies depending if the bottom side is plastered).  They then go on to
show optional ways to obtain this (12" oc, 16" oc, 24" oc).  Other spacing
may be used, but you would have to due the load calculations to determine
the size joists needed.  This information is all available in "Architectural
Graphics Standards" by Ramsey and Sleeper (for about $100).  Your library
might have the book

	Having thought about it, I guess that 24" wall studs isn't so bad. I
	don't like the idea of having non-standard spacing, but as long as
	*you* know what it is, that shouldn't be a problem. I can't say how
	many times I've worked in old housers and run into problems with
	finding the bleeping studs because they weren't spaced uniformly,
	let alone every 16".

	Roy

	I am currently thinking about 2x6 wall studs 24" on center
	verses 2x4 wall studs 16" on center. My main concern is 
	the 24" gap for the sheet rock. Is this an issue to be
	concerned with ??

	Ken

    Re: .10
    
    No
    
    I used 2X6 for walls in an addition of mine. Worked fine.
    
    Marc H.

Oh well one more opinion is probably worthwhile....

I like the idea of 16 OC floor joists for the sole reason that the floor will
tend to feel more solid and the underlayment will have more points to attach
to the floor.  Don't forget that the underlayment ties the floor together and
help provide rigidity.  I would definitely make sure that the underlayment 
is glued to the joists since this will prevent sqeaking and creaking (is there
a differnt?)

24" OC walls are fine when using 2x6 construction.  Again, pay attention to the
thickness of the sheathing since this will help prevent bowing.  Also, the 
sheathing provides the rigidity for the verticle studs so its important that
its a strong enough material.  The only other thing that I can think of when
going with 2x6 walls is that windows and doors will need extensions or will
need to be custom to fit the deeper opening.

Hope this helps - good luck,
Wayne

> 24" OC walls are fine when using 2x6 construction.  Again, pay attention to 
> the thickness of the sheathing since this will help prevent bowing.  

Is standard 1/2" CDX plywood good enough?  I specified 2x6 construction on
a recent project and the carpenter said that he still wanted to use 16" OC.
So we did it that way, with 1/2" sheeting and clapboards.  I guess he
wanted narrower spacing to attach the sheeting and clapboards in more
places.  Was his attitude just prejudice, or is there justification?

	Thanks,
	Larry

    re:last.
    	the 2x6 on 16 might be a little overkill for the walls.  5yrs
    ago we built a cape using 2x6x12' and 1/2 CDX.  Was heavy standing the
    walls up, but not problems with anything.
    
    re:sheerock.
    	No prob with the 24" & sheetrock.  best to us 12'ers and hang
    the horizontal.  Less tapeing that way and follows the stud better
    with only 4' runs incase of any bows.
    
    JD
    

    
    I agree with .12 on carefully fixing the underlayment.  In removing the
    insulation in our basement (9yrs-old Garrison) recently, we found that
    whole lines of nails had missed the joists.  The floor had been very
    squeaky when we moved in, and was all screwed down now with 2" deck
    screws. Even with that, there's still too much spring in the floor for
    my liking - and that's with 16" O.C.
    
    One of my books suggests the use of T&G particle board flooring - close
    to 1" thick and at about $12 a sheet, is cheaper than plywood.  I've
    used this in renovations and it is much stiffer than ply - even over
    old fashioned 3x5 (12' span) joists.  Is there a reason why particle
    board is not popular in the US?  You don't need subfloor, it has no
    voids and has a hard face.  (I notice that HD stocks it).
    
    You mentioned 24" OC in the family room?  If you have kids and they are
    as heavy footed as my little one is, you might want to think about
    their effect on a springy floor...
    
    Colin
    

Our main concern is bowing between floor joists.

We've decided to leave both floor and walls at 24"OC.  We will be doubling
up the floor joists giving 12"OC where there is linoleum or ceramic tile.

This includes:	1st floor: kitchen 
			   breakfast area
			   1/2 bath
			   laundry room
			   mud room
			   foyer 
		2nd floor: 2 full baths

left at 24"OC:	1st floor: Formal living room
		2nd floor: 4 bedrooms
			   hallway

The family room will be on a slab with a frost barrier and radiant heat.  
The dining room will have a hardwood floor.

The reason:

switching from 24"OC to 16"OC:		$6200
24"OC and doubling up under tile:	 $900

Thanks for all the input!

bill

    Did the builder offer any explanation of the price difference?  It
    sounds way high to me.  Using the prices from a local lumberyards
    flyer, and assuming a 28 x 46 house size, I come up with about a
    $150 increase in lumber costs.  There would also be 12 more joists
    to install on each floor and more nailing to do on the subfloor.
    Still, I wouldn't think thats more than a day or two of labor.

The main part of the house is 36' by 28' using 2x6s in the walls

Doing 24"OC he'd use 2x12s on 1st floor and 2x10s on the 2nd
Doing 16"OC he'd use 2x10s on 1st floor and 2x8s  on the 2nd

I can't remember what the construction style is called, "stacking..."
but it's where the wall studs line up with the floor joists.  So,
both walls and floors are either 16" or 24" OC.

How does your math work considering the walls too?
I'm also curious as to the price difference...

My first home was built to my spec's with 2x6 24" oc (walls). Biggest mistake
I made on that house. The sheathing bowed with the stud spacing and the siding
moved with it. I did have 16" oc 2x10 floors with solid blocking that were very
solid.
For the few extra dollars, go with the 16" oc walls and joists!

Ross

    I also agree with going for 16" oc for walls and floors. I didn't
    think code allowed for 24 oc floor joists. My house even has 2x6 on 16"
    centers on walls. Makes for solid/rigid construction. You may be 
    sorry if you you want to put ceramic tile down somewhere on floors 
    w/24" joist spacing. 
    
    /bd  

    My parents house was built with 2x10s spaced on 12" centers in the 
    kitchen/living/dinning/family areas and 16" centers in the bedroom/bath
    areas. The walls were 2x6 on 16" centers. Nice solid contruction. You
    didn't have to be careful about floor bounce if someone was playing a
    record on the stereo system. I would not recommend 24" spacing for 
    floors or walls.
    
    

Well... Here's what we're doing.

1st floor 2 by 12 24" OC
2nd floor 2 by 10 24" OC

However, where there's linoleum or ceramic tile we're doubling up the
floor joists so that it's actually 12" OC.  The walls will stay 24" OC
and line up with every other floor joist.  The doubling covers about 2/3 
of the first floor.  The family room which hangs off the end with a
cathedral ceiling will be 16" OC because of traffic.  The $$$ is much 
less then going all 16" OC and the walls will be better insulated as one
reply alluded to.

bill