Need a quick answer. Does anyone know...

Does anyone know what the guidelines or IRC codes are for the amount of time that concrete foundation forms must be kept on?

Foundation walls are 8’ 10" and the foundation wall is 10" thick. They poured yesterday morning and the forms were taken off this afternoon.

Doing a phased inspection for a contractor (go figure! :wink: ). They want me to check the site out, prepare an ongoing report and do a final, pre listing inspection.

Here are some details and pictures. Please comment as you see fit.

NACHI helps.

Little Indian (eastern, not American) woman whose husband has WAY too much money and was a builder (money guy only) and built some pretty decent tear-down McMansions. The husband has gotten out of the business, but the wife likes it. (Around here, the Indo-Pak community is very big.)

She “built” her first house (She is the GC) and had me look at it (spec house) and she ran into many problems (she hired the cheapest subs. Go figure.)

Now, she wants me to “inspect” (read, check out and report how well the subs are doing and correct (or fire) them depending or their work.

You have to understand that the codies in this area (northern Chicago sububs) are usually good, professiona guys, but they have very little time on site (an average 4,200 SF SFH has only about 45 minutes, total, of local code inspector time on site during the whole process).

Footings were poured (with 2 x 6 forms and the concrete only went down about 7 to 8 inches). I never got a chance to check the rebar in the footing (duely disclaimed). The keyway was formed with steel angle irons, dragged through the wet cement (only 1 1/4" deep and in a V form. Picture 1.)

Then they put up the forms (about 3 days after the footings were poured). Please note the rebar (only at the bottom of the forms) which were tied with old, rusted wire. (Picture 2).

Drain tiles were just flexable black perf, not shedule 40 PVC. Seems like they want to claim both interior and external drain tiles, but the just run them through the footings, depending on the perimeter (many in and outs). (Picture 3, outside corner in an indentation.)

The concrete was poured yesterday morning, but was still wet and “could easily syill write my name in the top” on yesterday, early evening (pciture 4).

There was a garage (less deep footings and foundation) at the front east, and a basement walkout on the east side. The footings for these areas had no protruging rebar (for marriage into the adjacent foundation wall). There erre also big gaps, and embedded wood (from forms) at the basement walkout interfaces with the higher footings and foundation walls.

Please answer the “how long before you can remove the forms” question first, then, any comments?







Sorry. Hit the 5 picture max limit. Here are the other pictures.





Here’s some food for thought from the American Concrete Institute:

You are good Michael

Thanks. Good advice (spread the liability to the subs :mrgreen: ).

Also, please note. The soil was compressable clay.

You too, Brian.

Mike always tries to be the hero :mrgreen:

I’ve never been in the foundation pour business, but I do know that all poured concrete must be given time to cure. IMO…24 hours is too early to remove forms.

During the curing period, the concrete surface should be kept wet down by repeated hosing with a fine mist. Such a hosing down process should be done at least twice during any 24 hour period for about three days. Then the forms can be removed.

My Googler was just running at top speed today that’s all. :stuck_out_tongue:

Is that the contractor I referred to you a couple of weeks ago?

Yeah basic 101 is the longer it is kept wet. the better the concrete.
Same with plaster.The slower the cure the better.

William, I have been working in residential and commercial poured concrete foundations for 7 years now and on most residential work the forms will be removed the following day should be fine if the concrete is a proper mix and not watered down. I am working on a large commercial project right now where we did one of the pours yesterday walls are 10’ high 12’'thick with double mat rebar to the top , poured 90 cubic meters ( yards for the americans) of concrete yesterday afternoon and spent today removing the forms.

Sorry William I just reviewed the pictures, there are a couple of things that bother me. The wood imbeded in the wall is an incorrect method of closing the forming gap at the step, it should be closed on the outside of the form ensuring that concrete fills right to the step and not leaving an open gap. Also the footing at the step should not end at the top and the start again at the bottom. The framing should come out past the step so the concrete extends out past the step and joins the lower footing, the engineers and inspectors up here would never let us do it the way it is pictured. Hope this helps, if you want any more info send me a PM I will try to help.

Here is an interesting article.

I have to agree with Jerry. I would be more concerned with some of the other issues. If they had the proper mix this time of the year in the climate that we share (not very nice), then the concrete should be fine. I would be more concerned with what Jerry stated and the drain tile not being pvc. When do they intend on starting the deck for the first floor?

CSA document I read many years ago recommended 72 hours for forms to be in place with exposed surfaces to be covered with burlap and wetted when necessaery. When I tested concrete for the NB Dept of highways, three days was requied also. The concrete forming company had to have someone come back to the site on weekends to wet the burlap.

No. At least I don’t think so. Call me.

My hero! (insert dramatic and (if you are sick) romantic music here :mrgreen: )


BTW: No rebar beyond the bottom 2 feet. Walkout looked real funky (and thanks for your contribution). I understand, do not leave wood behind!

No “marrying” or rebar from the upper footings (garage) to the foundation wall.

And the drain tile arangement is just plain silly.

BTW, part 2: What about backfill before bracing or beams and floor joists installed. IRC does not seem to like it.

At the top of the forms was tarp (flying in the breeze, picture 1).

They also sprayed some silver stuff on the exterior wall and the interior wall of the garage area (picture 2). The soil is expansive clay. Usually see, at least, asphault (damp, not water proofing, in this area).

Then, there was this area (Picture 3). This was the inside corner of the basement walkout. Garage footings to the left and the bottom of the basement walkout (interior) to the right.

BTW3: When i looked at the pour, about 8 hours after the pour, I still could put my finger into the concrete and make a 3 inch hole. It did not refill.

There was liquid water on top of the pour, in the forms, at 8 hours after.

Ideas, comments and great thoughts welcomed.




On my projects the forms always get stripped the next day, never had a problem.

I think Michaels post is the most accurate. The reality is, there are too many variables to take into consideration, but that’s best left to the experienced professional.

I’ve worked on many projects where the forms were stripped within a few hours, and I’ve worked on projects where forms had to remain for up to thirty days. I’ve also worked on “slip-forms” (in dam construction) where the form is never stationary for more than an hour.

So I think the safest answer would be (unless you really know concrete) to refrain from making any comments as to the time frame for form removal.