How to tell if builder put rebar in foundation

I have a fairly paranoid extended family member who is currently having a home built. They are concerned the builder may not have put rebar in the foundation. Anyone have a creative trick I could use to help get them some piece of mind. I’ve thought about trying to use a strong magnet…

I’ve never tried it, but there is this:

http://boards.straightdope.com/sdmb/showthread.php?t=482746

These work pretty good for locating rebar (non-invasive).

http://www.zircon.com/tools/metalliscanner-mt-6/

Great solution, Brad…and 6" deep in concrete for ferrous and non-ferrous metals. My link shows that in post #5.

Kyle watch the short demonstration video in Brad’s link.

It is unfortunate to express concerns on whether or not the foundation reinforcement has been installed per whatever plan or agreement after the fact.
It would have been advisable to have had a testing firm do a pre-inspection of the concrete foundation prior to the pour.

All items covered on this checklist would have been covered.


The time it will take to verify that all the rebar was installed with the Zircon will be endlessly tiresome and not that accurate.

I would suggest that a Qualified Home Inspector be hired to inspect all other phases of the Home being built so as to set aside any future concerns of whether material or workmanship might have been left out or eliminated.

Thank you guys. I am looking into the links shared.

https://www.grainger.com/product/3RDN5&AL!2966!3!50916697077!!!g!82166510037!?gclid=Cj0KCQjw4vzKBRCtARIsAM3l8OAUPUX0bjND2J4zjLbc_yZelawj-zjjHGfTdagH6OjzQC-I0aDD13gaAp05EALw_wcB&cm_mmc=PPC:+Google+PLA?campaignid=175662957&s_kwcid=AL!2966!3!50916697077!!!82166510037!&ef_id=WKdwsAAAAZC7yvy0:20170707224129:s

is another option lol

I’ve been using this scanner for years. Works really good to check reinforcement in block walls.

Yep… MT-6.

I got the full story from the horses mouth yesterday on why they are concerned. I’m afraid the story may have some validity to it. Here it goes.

My wife’s grandpa (who is a retired union carpenter and his wife have been keeping a close eye on this new build that is being done for their daughter. The day before the foundation was scheduled to be poured they went out to the site and noticed that the rebar and form boards were set at 24 inches when they were supposed to be 36 inch walls. They brought this to the builders attention and did other various things to try and make sure it was corrected. Two days later they go by the site and the foundation is all poured.

They are skeptical that in that short amount of time the rebar could have been put in the top 12 inches forms set and everything poured. Apparently they have been up in arms about this the last couple of months with the builder and various local building authorities the last couple months while the home is now nearly finished. They are likely going to end up paying a sonar or x-ray type company to come out and try to get some proof one way or another either for peace of mind that there is rebar or the alternative…

Main question from here is.

What if there isn’t rebar in the top 12 inches, how detrimentle could that be in the long haul?

I could only imagine what a process of correcting something like this would be like if they find out that their hunch is correct.

Could you explain what you mean with this statement?

I would assume he meant that the foundation walls were originally set 1 foot too short. If they raised the form boards and didn’t also raise the reinforcement steel, that could be a problem IMO. Using the MT-6 can determine if there is continuous rebar in the top of the wall or not…just keep it away from any anchor bolts or sill straps.

My confusion seems to lay on the fact that I never asked if this was a basement foundation like is always on my mind due to this area.

Is this a stem wall that is just 2’ or 3’ or frost wall that we are talking about?

The minimum code requirement is (1) #4 bar 12" from the top.

If that is the case, I agree that would be easy to detect with the sircon.

Brad’s assumption is correct. We mostly have crawl spaces in my area. The concern is that the concrete may have been raised 12 inches without raising the rebar.

I did not read all of the above comments, just the first 3 or 4, but I would question why he mistrusts his contractor. Did he check this guy out? Do the plans have a structural detail that shows what rebar goes where? If so, does the contractor have receipts for the rebar? Doesn’t the city where he lives inspect the job as it went along?

Oooo! Gotta get me one for my next inspection!

No worries… you are only minutes behind Orting when Rainier goes kaboom, so that 12" won’t mean carp! :shock: