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Poured foundation wall rebar questions

RobKress's picture

Hi all,


I've got a question for the concrete folks here....


Building a new home in Cleveland, Ohio.  I have gotten two quotes from poured wall concrete contractors and had some questions about the differences.


Specifically, one of the contractors quoted no rebar in the garage walls (4' frost wall) while the other of course did.  Is there some significant story here with the rebar.  Of course more rebar is better (generally), but is there any reason to absolutely require it in the garage frost walls? 


How much rebar is standard in a poured wall?  The one contractor specifies 1 horizontal row in the 4' frost walls (walkout basement on two sides) and 3 horizontal rows in an 8' high wall.  The other contractor did not specify but his overall allowance for rebar is 4 times higher.


And one last question...... is it worth it to get the contractor to leave the forms on the wall for 2 or 3 days?  I expect this would either cost me more money or some serious coaxing (like maybe requesting the pour on Friday, form strip on monday).  But I understand that keeping the forms on the wall helps the concrete cure better and reduces the likelihood of cracking.  Or is there some other secrete that I should be requesting to get a better cure without cracks?  The standard that I have seen is to pour and strip the next day.


The bids are very close but the one without the rebar in the garage frost walls in the higher bid and frankly the one I feel a little more comfortable with.


Choosing my foundation wall contractor has been my toughest road so far.


Any help greatly appreciated.


Thanks


Rob Kress

(post #92562, reply #1 of 3)

I live in a class 4 seismic zone, so my response may not be relevent. 


I'm currently doing a foundation and  the walls are spec'd for #4 bars @ 2' centers vertical imbedded in the footing and horizontal # 4's at 12" centers. (stepped foundation, 4 foot to 9 foot stemwalls)


Rebar is good and I wouldn't leave it out under any circumstances.


However, your local code should specify.


Personally, I like to leave the forms on for a couple days anyway, but if they're stripped early, just keep the concrete damp...with a sprinkler, or drape some burlap over it and keep that damp if the weather is hot and dry.


 

 

(post #92562, reply #2 of 3)

Your plans should specify all the foundation hardware. There should be a cross section of a typical footing as a plan detail. It's on the most minimum of plans usually. There is no reason that the garage concrete should have any less requirement for steel than the house. If engineering was required then all the details should be in the engineering documents. The contractor that said no steel must have missed something on the plans. With a 4 foot wall around here we have at least two horizontal strings in the footing and every foot in the stem wall. If the wall is higher than 2' then you need vertical rebar every 2' or whatever is specced. I know for sure we use more rebar on the west coast because of earthquakes but only one horizontal in 4' seems kind of skimpy.

The only reason most will strip the next day is because it is less work when the concrete is really green. It can be pretty hard work stripping forms on a good day. Concrete has a way of locking in stakes and the lower boards of the form. There is a short window to getting those pieces out. If that stuff won't come out then it gets buried to attract termites. I wouldn't ask the contractor to wait a few days to strip the forms. It would be asking to make the work a lot more backbreaking. Try the weekend schedule trick and maybe you will see him on Monday but I bet he sends someone over Saturday to at least pull stakes

If you want to help cure the foundation then protect it from the hot sun and spritz it with water frequently for a few weeks.

We may be slow, But we're expensive.

Mike Callahan, Lake Tahoe, Ca.

(post #92562, reply #3 of 3)

New Home, sometimes I would ask, " what do your blueprints call for", then another question might be, who drew your blue prints?  RobKress, go with the formsetter you feel comfortable with, with the rules being, You want some rebar, and are willing to pay extra for it. I would also read Notchmans post a few times. I didn't read anything about  a keyway in your footing, and or verticle rebar. Good Luck with your new home, and I mean that. Jim j