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Conference 7.286::home_work

Title:Home_work
Notice:Check Directory (6.3) before writing a new note
Moderator:CSLALL::NASEAM::READIO
Created:Tue Nov 05 1991
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2100
Total number of notes:78741

142.0. "Concrete - Footings" by BAEDEV::RECKARD () Fri May 15 1987 15:38

    I'm replacing an external stair.  I've already torn down the old rotten
    one.  Half-way up the old stringers were two 4x4 supports _sitting on_
    (not bolted to) a couple of concrete footings.  (Actually the 4x4's were
    nailed to a 2x 6? which sat on the footings and was buried, or at least
    flush, with soil.)
    Can I somehow use the existing footings?  In the same way as the old one
    was constructed?  Can I embed a bolt in the old footing?
    As I understand it, even tho the stringers are 15' long, the one pair of
    supports is sufficient, and does _not_ carry alot of weight, but is there
    mostly to reduce wobble and sway (technical terms  ;^).
T.RTitleUserPersonal
Name
DateLines
142.42VINO::KILGOREWild BillFri Jan 16 1987 21:478
    
    "Well," you might say, "if I'm going to put a smallish concrete
    support in the ground, why not just dig a round hole and pour?"
    
    One advantage of using a Sonotube is that it creates a support with
    very smooth sides. When winter comes, there are no ragged surfaces
    for the frost to grab onto and pull the whole thing, little by little,
    out of the ground.
142.1Stairs = small, ascendings decks?WELFAR::PGRANSEWICZFri May 15 1987 15:575
    Try using the same hardware used for deck building.  You know, the
    brackets that bolt to a steel rod and then nail to the post.  Keeps
    the wood from contacting either ground or concrete.  I know you
    already know this but use pressure treated lumber throughout.
    
142.2Just keep it from the concreteARCHER::BMDLIBFri May 15 1987 17:1119
    I think what you're asking is how to secure the post or beam or
    stringer to the concrete footings.
    I was going thru the same thing when I set my tubes for the footings
    for the 14x20 deck. Since the deck was fairly low, I planned on
    resting the 4x6 beams on the footings with no wooden posts in between.
    Since I don't have the beams yet, placing some sort of brace in
    the wet concrete and then hoping the beams were perfectly straight
    to fit in the braces (now permenently attached to the concrete)
    didn't seem like the way to go.
    I asked around, and the overwhelming majority said "that thing is
    going to be so heavy, just rest the beams on some piece of metal
    to keep it from direct contact with the cement, don't bother with
    attaching it to the concrete".
    If you really feel you need to connect whatever piece to the footings,
    I would use some L-shaped brace that you can cement-nail to the
    footings and lag-bolt thru to an identical piece on the other side.
    
    
    
142.3AUTHOR::WELLCOMESteveFri May 15 1987 17:317
    You might just drill 1/2" diameter holes a couple inches deep in
    the tops of the footings with a masonary drill, drop in a couple
    of 1/2" diameter x 4" long steel rods (bolts with the heads cut
    off, maybe), and drill mating holes in the ends of the posts to
    slip over the rods.  All you need is something to be sure the
    posts don't slip off the footings. 
    
142.4anchors aweighMYCRFT::PARODIJohn H. ParodiFri May 15 1987 20:1812
There's also a jasper (I think it's called a bolt anchor) you can get
to secure a bolt to the concrete.  You drill a hole that is exactly
the size of the anchor, and drop the anchor in the hole.  The action
of tightening down the bolt causes the anchor to spread and hold tightly.

I think they are normally used for lag bolts but you could try for a
bolt with threads on both ends.  Then you could hold the posts (I've
heard them called "kickers" when they support risers that way) down
with post anchors.

JP
142.5this isn't Kansas, Toto!YODA::BARANSKI1's & 0's, what could be simpler?!Sun May 17 1987 20:3711
I really don't like the ideas put forth in the past couple of notes for securing
the deck with bolts, or even just having the deck sit on the footings with no
mechanical securing.  I just have this picture of the deck taking off in a
windstorm...

*I* would sink some heavy duty metal brackets into the footings with reinforcing
rod through them, and then drill and heavy duty bolt the beams to the bracket,
or maybe skip the bracket and bolt the beams *through* the columns side to side.
(so you can replace the bolts if need be).

Jim. 
142.6Nothing sinks in hard concreteARCHER::FOXMon May 18 1987 16:5410
    re .5
    That sounds secure enuf, but how are you going to do that with
    hardened concrete? We're all assuming you're don't have the luxury
    of "sinking" something in wet concrete.
    I would try not to stress the concrete too much as you don't want
    to crack it. There's a greater chance of that happening than a
    gust of wind throwing it off the footings. After all, how long was
    it just resting on them before you got there?
    John
    
142.7Overkill contest #1140WELFAR::PGRANSEWICZMon May 18 1987 18:358
    Better yet, why not just get rid of the wood all together and make
    to whole shooting match reinforced concrete!  ;-)  Let me see that
    baby move even in tornado!
    
    Overkill in certain instances may be justified but I don't think
    this is one of them.  I think any of the solutions offered would
    get the job done more than adequately.
142.8Must footings go below the frost line ?SMAUG::FLEMINGMon Jun 08 1987 11:5512
    I'am building a small deck that's supported by a ledger and five 
    footings. The ledger board is nailed to my foundation. The footings
    are eight inch diameter sona tubes. I've had trouble digging the
    footing holes four feet deep. Three are four feet deep, one three
    feet deep and one only two feet deep. The two shorter holes aren't
    that way for lack of effort. I dug out rocks bigger than basketballs
    but finally hit rock that just couldn't be dug out. My question
    is this; is it really all important to get footing down four 
    feet ? Has anyone had any experience, good or bad with footings
    that didn't go below the frost line ?
    
    
142.9BEING::WEISSTrade freedom for security-lose bothMon Jun 08 1987 13:046
The intent of the footings is to get a solid bearing surface below frost line. 
If the rock is really too big to remove then it's OK to set the sonotubes right 
on the rock.  The rock itself becomes your footing, and it goes below the frost 
line, for sure in the 3-foot hole, and close enough in the 2-foot.

Paul
142.10It depends on drainage!DRUID::CHACETue Jun 09 1987 18:3614
     .1 is correct.
    
     As for your question about anyone having trouble with footings;
    Yes, I've had trouble. A great deal depends on your drainage, and
    the type of soil you're working with. The SOIL doesn't expand, it's
    the water in it. Thus, if the soil is very well drained, there will
    be little or no expansion (so no trouble). In my case I had gone
    down 3.5 feet in very poorly drained soil which has a lot of clay
    in it. Last winter two of three footings lifted 6". So this year
    it's go down four feet with very large holes. Install 3' diameter
    cement footings 6" thick at that point and then backfill with gravel.
    I shouldn't have any further problems and I doubt you will either.
    
    					Kenny
142.114 foot deep footingsFRAGLE::STUARTThu Jun 18 1987 15:3510
    
    
    If you live in a town that will inspect the footings some building
    codes require a 4 foot deep footing. You also may want to look into
    a building permit if you haven't already. But it sounds like your
    footing will be fine.
    
    
    Randy
    
142.12Footings "below frost line or on bedrock."DELNI::OSTROMAndy Ostrom Networks Mktg. 272-7132Tue Jun 23 1987 18:005
The Mass Building Code (Article 21) states that all footings must be either 
below the frost line or "supported upon bedrock."  (Or words to that effect).  
I don't have the building code at work, but I can look up the exact wording 
tonight if you like.

142.13Is the footer below the ankler? :-)30519::YANKESWed Sep 23 1987 15:1212
    
    	I'm in the process of digging out part of my back yard for a
    patio.  Lowering it down to the basement floor level means removing
    around 3-4 feet of dirt right beside the house.  The digging is
    going quite well (almost done :-) but someone this weekend said:
    "Are you down to the footer?  If so, you might have freezing problems
    since the footer would now be above the frost line."
    
    	This same person said "not to worry" since it could be insulated
    if I was down to it.  However, I personally couldn't recognize my
    house's footer if it came up and bit me on the nose.  What is it
    and how do I know if I need to insulate this critter?  Thanks!
142.14He's right - put in insulationALIEN::WEISSTrade freedom for security-lose bothWed Sep 23 1987 15:4217
I think if there was 3-4 feet of dirt up against the foundation wall there that 
it's a pretty safe bet that the footer is only a little bit further down.  The 
footer is just the bottom of the foundation - a concrete pad that they pour to 
put the walls on top of.  If the bottom of the footer is not below the frost 
line - the deepest that the earth will freeze, which is about 4 feet in New 
England - then the frost can crack the foundation by freezing underneath it and 
lifting part of it.

And your friend was right, you can solve this problem by putting down 
insulation under the patio where it butts up against the foundation.  If you're 
right down to the basement floor, I'd put in at least 1" foam extending out 2' 
from the foundation, and maybe as much as 2" extending out 4'.  If your patio 
is 16' wide along the house, it would only cost about $40 to go with 2" 
extending out 4', which I think would be worth it compared to the potential 
cost of repairs if you don't put in enough.

Paul
142.15know your footing from your...VICKI::MONTIVIRDIWed Sep 23 1987 15:4919
         Your footing is that section of your cellar which provides
    a base for the wall itself.  It is usually 12 inches thick, ( your
    cellar wall is 8 inches).  The diagram shows the relationship:
    
                     --------
                     |      |
                     |      |
                     |      |
                     |      |
                     |      |
                     |      |
                     |      |
                   __|______|__
                   |          |       <---- footing
    
    If you expose your wall down to the footing you run the danger
    of getting frost under the footing and possibly cracking it.
    If you have to expose that much you can probably insulate it
    with rigid foam insulation.  Hope this help, happy digging.
142.16Am I missing something?ARCHER::FOXWed Sep 23 1987 16:076
    Excuse these possibly dumb questions but...
    Why are you digging so deep for a patio? Why not dig just enough for
    your base and whatever surface the patio will have?
    I have never heard of trenching out the entire area down to the
    frost line for a patio!
    John
142.17Thanks for the quick replies!30519::YANKESWed Sep 23 1987 16:4629
    
    Re: .1
    
    	Thanks for the confirmation.  The guy that warned my brother
    (who then warned me) is supposedly making up a list of ways of
    insulating it and foam was at the top.  You're right -- it sure
    is a low low low price for long-term peace of mind!
    
    Re: .2
    
    	Aha!  I have hit the footer.  When I was digging, I noticed
    an area at the bottom that came out a few inches further than the wall.
    Thanks for the picture!
    
    Re: .3
    
    	Well, John, I agree that the depth might be a bit unusual for a DIY
    patio project, but my basement had a (leaky!) bulkhead that I really
    despised and the wife and I wanted to have a walk-out patio instead.
    Next summer, we're planning on putting a deck off the first floor
    above the patio (and screening in the patio to keep those little flying
    critters away!) which further dictated having the patio at the basement
    floor level.
    
    	The sides will have a 3-4 foot retaining wall but the front will be
    terraced going out of the patio to lessen the underground feeling that it
    might otherwise have.
    
    
142.18Curious.ULTRA::BUTCHARTThu Sep 24 1987 15:526
Im curious.  I have a walk-out basement (that doesn't have problems).
I assume the builder simply dug deeper so the retaining wall still
goes down 3-4 feete from the basement doorsill?

/Dave

142.19ALIEN::WEISSTrade freedom for security-lose bothThu Sep 24 1987 17:188
> I assume the builder simply dug deeper so the retaining wall still
> goes down 3-4 feete from the basement doorsill?

Yup.  Typically called a frost wall.  It's usually just a very deep footing, so 
if you dug it up you would still find the top of the footing in the normal 
place.

Paul
142.20STAR::GOLDSTEINAndy Goldstein, VMS DevelopmentFri Sep 25 1987 21:325
>    	The sides will have a 3-4 foot retaining wall but the front will be
>    terraced going out of the patio to lessen the underground feeling that it
>    might otherwise have.
    
Uh, have you worked out where the water is going to go when it rains?
142.21But where do I put the diving board?30519::YANKESMon Sep 28 1987 13:097
    
    	Well, I figure that this winter I'll have enough water in the
    bottom for an ice-skating rink and then after the spring rains I'll
    have a swimming pool!
    
    	Just kidding.  I'll have a drain leading into a dry-well.
    
142.42don't move, groove !CASCO::PASCOMark 'PASCO' PascarelliWed Dec 23 1987 11:5726
142.22To use footings or not to use footingsDREAMN::FLAHERTYTOMMon Jan 18 1988 20:0630
    OKAY, I've just spent an hour looking for an answer to my foundation
    problem and didn't see one.
    
    A crack developed in my wall from floor to ceiling and guess what??
    You got it, water leaked in. The foundation is 2 years old.
    I hired a contractor to fix it. He dug up the outside all the way
    to the footing (I believe) and did quite a bit of work on it.
    He filled the crack (with what, I don't know) he then put sealant
    over the whole area and did the same on the inside. Well, it rained
    and rained a few times after and nothing leaked in.
    Now my wife calls and today's mini-thaw is leaking in.
    
    The contractor want's to talk to the person who works for him
    that did the actual work, but he was telling me if the footings
    are not below freezing or there are no footings then it could have
    re-cracked and therefore he will probably tell me how he is not
    responsible.
    
    Which leads me to my two questions. 
    1 - if the footings were not below freezing or non-existent would'nt
        I be having a lot more problems than this one crack?
    
    2 - if the bottom of my foundation wall is four feet below ground
        level, do I need footings (still further below)??
    
    Thanks for any advice,
    I'm ready to go back to renting and let the landlord have these
    problems....<:)
    
    Tom
142.23to foot or not to footNETMAN::SEGERthis space intentionally left blankTue Jan 19 1988 00:4117
When I added on to my house I watched the guy with the backhoe do his thing.
When he got down to the footings, shazam!  no footings...   he told me that
was not uncommon.

When the forms people showed up they too told me footings are not required.
Actually I was told that the soil my foundation was set on PROBABLY didn't
require footings.  Needless to say, I sprang for the extra $$$ for some piece
of mind.

So, to get back to the original question, it sounds like it's strictly a 
question of the soil conditions, though I would expect most contractors to put
them in.

As far as your contractor trying to whimp out if you don't have footings, why
didn't he tell you as soon as he found out rather than completing the job?

-mark
142.24"foot the bill"FRSBEE::DEROSABecause A Mind Is A Terrible ThingTue Jan 19 1988 11:008
    When I added on to my house two summers ago, the builder told me
    that the bulding code (at least in my town) requires footings. Also
    the town building inspector made sure they were there. They were
    at LEAST 4 ft. down.
    
    In my opinion footings should definitely be used to keep the foundation
    wall from shifting or sinking or even cracking.
     
142.25AUTHOR::WELLCOMESteve Wellcome (Maynard)Tue Jan 19 1988 11:218
    My experience has been that it's incredibly difficult to patch a
    crack in a concrete wall so it doesn't leak.  The forces of freezing
    and thawing are *incredible*, and the wall has to move just ever-
    so-slightly to open up the crack again.  
    Not to discount the possibility that the contractor did a lousy
    job, but I think it's much more likely that he did the best job
    he could in the circumstances.  
    
142.26Hairline or Grand Canyon?VAXWRK::BSMITHNoters do it with keypadsTue Jan 19 1988 11:499
I think footings have to be 4'6" below grade.  Mine are about 4' in the front 
of the house (split).  Is the grade pitched away from the house??  Do you have
gutters??  Do you have footing drains??  The biggest problem I have with 
moisture coming in is from having no gutters on the roof.  How big is the 
crack??  Hairline cracks are 'normal'.   I watched a this old house show
where the addition had no footings, reason being that the ground was packed
enough so they weren't neccessary. 

Brad.
142.27Only hairline...Still a problemDREAMN::FLAHERTYTOMTue Jan 19 1988 16:1121
    .4
    
    It is graded away from the house. (Also a split)
    I DON'T have gutters.
    I have foundation drains that work. (Water comes out the end in
    a rain storm.)
    The crack at this point is hairline. Not much water comes in yet.
    Before I had it repaired, about four times as much water was coming
    in.
    
    If the water is going into
    the drain and it's not a water table problem, would gutters make
    a difference?
    My soil is very clayey(?)
    
    It's especcially a bummer because the house is a split and I would
    love a family room down there.
    Am I forever going to be patching leaks in my wall no matter how
    small or can I do something permanent?
    
    Tom
142.28Relieve the pressureCHART::CBUSKYTue Jan 19 1988 16:4423
    If you have foundation drains that work, presumably directly below the
    crack, I would have the area opened up again down to the foundation
    drain. Repair the crack with some type of flexible caulking compound (I
    have used GE Silicon for this with good results). Then install a
    section of peforated drain pipe vertically from the foundation drain up
    to almost the surface with a cap on the top. Position this pipe so that
    is aligns with the crack. Then back fill the hole with crushed stone
    for about two feet around the pipe. 

    The flexible caulk should seal the crack and but allow minor shifts in
    the foundation due to expansion and contraction. The pipe and stone
    should relieve the water pressure that is obviously building up near
    the crack and allow the water to fall to the foundation drain and
    then away rather than forcing its way through the crack.
    
    Question, Is this crack in a long wall with no breaks (door way
    openings) or corners? A foundation wall of with a straight run of 40
    feet or more is considered LONG and prone to cracks. I have a front
    foundation wall of 44 feet and right about in the middle is a floor
    to ceiling crack. The wall should have been poured with an expansion
    joint to prevent the problem.
    
    Charly
142.29Relieve what pressure.. Water or MINE!!DREAMN::FLAHERTYTOMTue Jan 19 1988 16:5713
    Good advice .6
    
    I like that idea about a vertical drain pipe!!
    
    Yes, my wall is long. It's 42ft with an opening for a bulkhead at
    on end. The crack is just about in the middle of the wall.
    (FYI. I have another similar crack in the middle of my side wall
    in the garage that's 24 ft long. The wall, not the crack <:) )
    
    Brings a question to mind. What's an expansion joint and can one
    be installed now, post-construction??
    
    Tom
142.30You already have ONECHART::CBUSKYTue Jan 19 1988 17:5219
    There is no need for you to install an expansion joint now, YOU ALREADY
    HAVE ONE, and I'm not kidding. As long as it's not growing, it
    shouldn't be a problem. All you have to do now is seal it and keep the
    water pressure away from it. 
    
    The cause of your crack could also be settling or a combination, but
    the fix should work for both. Especially the part about directing the
    water to the foundation drain. 

    An expansion joint is a pre-determined break point in the concrete and
    in a wall can be achived by inserting a flexible material (could be a
    rubber or fiber seal) to seperate the two pieces. In side walks and
    road ways they usually divide the area up into sections and pour every
    other section and then fill in the missing sections after the first has
    set, so that there is a natural break or they can score the slab into
    sections with a special trowel to create a weak point. That way the
    cracks run across the road or side walk rather than any which way. 

    Charly
142.31do it insideRANGLY::MITCHELL_GEOya snooze...ya lose!Tue Jan 19 1988 22:088
    
    	Theres a product on the market called "Water Plug". It is like
    cement. You mix it like any patching compound. What makes this 
    product unique is that it expands as it dries thereby sealing the
    leak/leaks. There's also a paint that seals cement walls against
    seepage...why not try them both in concert...cant hurt
    
    				___GM___
142.32"Water Plug" = hydraulic cementPLDVAX::TRANDOLPHWed Jan 20 1988 13:091
    
142.33Yes, gutters will help...VAXWRK::BSMITHNoters do it with keypadsWed Jan 20 1988 16:3014
RE:.5>    
    
>    If the water is going into
>    the drain and it's not a water table problem, would gutters make
>    a difference?

Yes because you would put a discharge pipe at the end of the downspout
pointing it away from the house.  Think about it, right now you have 
probably a 42 X 14 (or so) square foot area that is directing all its water
runoff about 1 foot away from the foundation with now place to go but
down into the ground next the wall, along the entire length.  Gutters
removes this exposure to the wall.

Brad.
142.34MADMAC::REZUCHAThu Jan 21 1988 13:288
 I bought DIY vinyl gutters, hangers, and downspouts to get rid of the
drip of the porch roof onto the entryway stairs. The downspout dumps
the water very far away from the house. The vinyl gutters were very 
easy to put up and look good. I have a fieldstone basement which was 
always damp and it is _noticably_ drier down there now. 

 Kind regards,
-Tom Rezucha
142.35I think I'll stay a homeownerDREAMN::FLAHERTYTOMThu Jan 21 1988 16:0811
    Thanks for all the advice.
    
    I think i'll do a little of everything. GE silicone the crack and
    put in a vertical drainage pipe. Then put up gutters, which I wanted
    to do anyway for the porch and entrances.
    
    Of course, it won't be till spring....
    
    Thanks again, it's nice to know I'm not alone.
    
    
142.36Drainage illsODIXIE::ODENWALDERThu Apr 21 1988 18:528
    There are a few things to recognize. Reroute the water from the
    foundation because you may cause shifting in addition to leaks.
    Also try to put on a parge coat of quarter inch mortar for the
    exterior. Do the whole wall if it must be cosmetic otherwise just
    do one yard square for each crack and bury it. 
    
    Ode
    
142.37Backfilling around footing and foundationTOKLAS::FELDMANPDS, our next successMon Feb 20 1989 16:2452
    This seems like an appropriate note to ask this question, so here
    goes.
    
    We have a foundation for an attached garage already in place.  It's
    positioned at a slight angle and about 6 feet further back than
    the house, so a top view is:
    
    		  |house	    walkout basement door
    	|	  |		 __/
    	|	_________________||___
    	|garage	|X
    	|	| \
    	|_______|  \
		    Area of concern
    
    The interior of the garage has already been backfilled (that's another
    question, but one thing at a time).  The area directly behind the
    garage and on the outside (the left of the above picture) has also
    been filled, and is quite steep, so there should be no drainage
    problem there.
    
    The problem area is the point marked X.  This area hasn't 
    been filled, so that the top of the footing is barely visible. 
    There are a lot of boulders in the area, mostly in the 1 foot to
    2 foot diameter range.  The ground at that point does still slope
    away from the house, so that we don't have a pond there, but it
    obviously needs to be fixed.  The area to the right of that point,
    along the back basement wall of the house, slopes up sharply away
    from the garage, and then slopes down again, not quite as sharply,
    to accomodate the basement windows along the back wall, and then
    the basement door.  This area also slopes towards the back yard,
    although since we have no gutters, most of the runoff seems to move
    to the right, towards the basement door, and then towards the lower
    right, to the back yard, which really is much lower, though not
    as steep.
    
    The questions are this:  First, should we have the boulders
    removed?  I'm sure we could use some of them for landscaping, though
    I don't know if we could use them all.  Is it safe to call in some
    excavator/landscaper, and ask them to remove the boulders, without
    causing accidental damage to the foundation?  Should we wait until
    the ground has thawed?
    
    What should we specify for backfilling?  Should we just put in dirt,
    or should we put in gravel or something else, and if so, how much
    of each.
    
    Finally, as long as we have a certain amount of exposed foundation
    that will covered, should we bother putting tar or insulation on
    the exposed part?
    
       Gary
142.3812" CONCRETE FOOTINTGS?LEDS::PERKINSWed Sep 04 1991 11:3818
    We are just putting together specs to build a new cape home.  The
    builder gave us his specs and we are seeing whether they are what we
    want.  
    
    Question:  He has listed 12" concrete footings to support a 10" wall. 
    Someone had told me to upgrade to 16" footings to allow for more
    support.   
    
    Is that worth considering and, if so, what would the expense be to do
    that?   Considering the possibility of future resale, would the expense
    be worth it?  
    
    Please answer at LEDS::PERKINS.  
    
    Thanks in advance!
    
    Susanna
     
142.3912" which way?MAST::WEISSThu Sep 05 1991 20:4010
    Is that 12" wide or 12" tall?  The normal size footing for a 10" wall
    should be about 20" wide by 10" tall/deep.  The rule of thumb for
    footings is to make them twice as wide as the wall thickness, and just
    as deep.  8" thick poured concrete walls are typical in residential
    construction, resulting in an 8x16" footing size.  Local building codes
    may vary, so you may want to check with your local building inspector
    to get the best information.
    
    ...Ken
    
142.40VERGA::WELLCOMESteve Wellcome (Maynard)Fri Sep 06 1991 18:534
    Nowadays they are sometimes pouring walls without any footings at
    all...it depends on what the soil is.  Personally, being a
    conservative type I'd want to put them in, but if you have the
    right kind of soil you may not need any at all.
142.41Add rebar, not concreteMEMORY::MYERSCSSEWed Sep 11 1991 17:4810
    I concur with the previous replies that 10" depth is adequate for
    footings to support the 10" walls.   They typically use 2x10s for
    the footing forms so it may turn out to be slightly less.
    
    If you are specing a house (down to the details as you indicated),
    for added strength to footings AND the walls I'd be more apt to 
    spec 1/2" #4 rebar rather than deeper footings.   Also be sure that
    the footings are deep enough (48" frost walls in MA).
    
    /Russ