Ufer HAS to be in footing?

[makemenuconfig]

I got called by a builder to do a ufer. The footings were already poured, but the walls were not yet poured (thankfully). The stem wall was 24" tall with #4 bars at 8" and 20" all the way around the building. It's a slab inside the wall, so most of the wall will be buried. The builder didn't want any rebar coming out of the wall, so I used #4 bare copper and an approved clamp for to tie onto one of the lower 20' bars.

I thought this was code compliant, since 250.52(A)(3) basically says "One or more bare reinforcing bars not less than 1/2" diameter ... shall be encased by at least 2" of concrete and located horizontally in a concrete foundation, footing, vertical foundations, structural components, or members in direct contact with the earth." And this was a 20' #4 encased in more than 2" of concrete in a vertical foundation in direct contact with the earth. Simple, right?

No. The inspector who showed up said it wouldn't fly and needed to be in the bottom 2" of the footing. In this case instead of chipping out part of the footing, he said he would allow a 20' bar in the bottom of the wall as long as it was in the bottom and inside-side of the wall.
He cited:
- The ufer needs moisture in the concrete to work (so somehow the wall doesn't work)
- They don't want it attached to part of the structural steel, but rather a separate piece of steel (I've never heard this before, I usually use one of the footing bars)
- In the future it needs to go in the footing.

Thankfully there was extra 20' stick of rebar on site and the inspector let me toss one in the bottom of the form and clamp to that, so he still approved the inspection and I don't have to go back. I'm not in the business of arguing with inspectors. But code disagreements aside, is there a downside to attaching to part of the structural rebar or locating the clamp in the wall and not the footing? I'd like to know what actually works well or not.

 

[Joe.B]

250.50 All grounding electrodes as described...A(1) through A(7)...shall be bonded together... Where none...exist...A(4) through A(8) shall be installed and used. Exception: ...are not accessible for use without disturbing the concrete.
A(3) CEE ...within that portion of a concrete foundation that are in direct contact with the earth.

Nothing in A(3)(1) says it has to be a separate piece of rebar, at least the way I read it.

The best point of connection is the bottom of the footing, when available. If that's already been poured, it's not available. If an area yet to be poured will be in direct contact with earth and 20 feet or more of rebar is available that should be fine. If the entire foundation was poured then it's not available and I think they should allow the other options in 4-8 to suffice. I think it's unreasonable to deny an installation when the proper CEE was missed, but if the AHJ wants to be a stickler then technically it was available and it was missed, they could dig their heels in and say "fix it."

 

[infinity]

It has to be in the footing. Miss it and many jurisdictions require you to get out the chopping gun.

 

[Strathead]

The best point of connection is the bottom of the footing, when available. If that's already been poured, it's not available.

Sorry, but that isn't an acceptable argument in every place I have been. It was available during this phase of the construction. It is only "not available" if it is an existing building an no new footers are being poured.

 

[Strathead]

I got called by a builder to do a ufer. The footings were already poured, but the walls were not yet poured (thankfully). The stem wall was 24" tall with #4 bars at 8" and 20" all the way around the building. It's a slab inside the wall, so most of the wall will be buried. The builder didn't want any rebar coming out of the wall, so I used #4 bare copper and an approved clamp for to tie onto one of the lower 20' bars.

I thought this was code compliant, since 250.52(A)(3) basically says "One or more bare reinforcing bars not less than 1/2" diameter ... shall be encased by at least 2" of concrete and located horizontally in a concrete foundation, footing, vertical foundations, structural components, or members in direct contact with the earth." And this was a 20' #4 encased in more than 2" of concrete in a vertical foundation in direct contact with the earth. Simple, right?

No. The inspector who showed up said it wouldn't fly and needed to be in the bottom 2" of the footing. In this case instead of chipping out part of the footing, he said he would allow a 20' bar in the bottom of the wall as long as it was in the bottom and inside-side of the wall.
He cited:
- The ufer needs moisture in the concrete to work (so somehow the wall doesn't work)
- They don't want it attached to part of the structural steel, but rather a separate piece of steel (I've never heard this before, I usually use one of the footing bars)
- In the future it needs to go in the footing.

Thankfully there was extra 20' stick of rebar on site and the inspector let me toss one in the bottom of the form and clamp to that, so he still approved the inspection and I don't have to go back. I'm not in the business of arguing with inspectors. But code disagreements aside, is there a downside to attaching to part of the structural rebar or locating the clamp in the wall and not the footing? I'd like to know what actually works well or not.

From your description, the REBAR sticking up is usually tied together with all of the rest of the rebar thereby forming a valid tie point, however, an inspector is well within his right to insist on seeing the proper tying of the rebar to pass this. Sounds like that GC just needs a lesson. He wouldn't do it again if the inspector required him to chip out the rebar, and I wouldn't do it for him unless it was my mistake for not getting out there when I was called to.

 

[makemenuconfig]

From your description, the REBAR sticking up is usually tied together with all of the rest of the rebar thereby forming a valid tie point, however, an inspector is well within his right to insist on seeing the proper tying of the rebar to pass this. Sounds like that GC just needs a lesson. He wouldn't do it again if the inspector required him to chip out the rebar, and I wouldn't do it for him unless it was my mistake for not getting out there when I was called to.

No argument there. Perhaps I didn't describe well. I snapped a picture (before I changed it). Perhaps my question is better phrased "If a 20' piece of rebar in a buried concrete wall isn't acceptable, why? And why doesn't the NEC better explain the importance of it being in the footing?

 

[Joe.B]

Yup most jurisdictions will not allow that, and often AHJ's feel the need to be the teacher and get the ruler out. In my jurisdiction we require all foundations (and footings) to be inspected and I make a point of requiring the CEE to be installed prior to any concrete being poured. I have yet to have a situation arise where I would have to make the call as described in the OP, but if for some reason a footing got poured without an inspection and there was a way to get a code compliant CEE installed for the next pour I would probably allow it. If there were some situation where a foundation was inspected and approved without the CEE (maybe I was on vacation and my replacement missed it?) then I personally would allow one of the other options.

Back to the OP, do you know if the footing was inspected and approved prior to the first pour?

 

[wwhitney]

It has to be in the footing.

The code language reads to me that it is enough that there's a metallic path through copper wire and rebar (including rebar ties) to a region of concrete that is cast directly against the earth.

But if the footing is cast directly against the earth, with no rebar stubbed out, and the wall above is going to be waterproofed on the outside and has no earth contact on the inside, then I agree it has to be in the footing.

Cheers, Wayne

 

[Dennis Alwon]

The code language reads to me that it is enough that there's a metallic path through copper wire and rebar (including rebar ties) to a region of concrete that is cast directly against the earth.

But if the footing is cast directly against the earth, with no rebar stubbed out, and the wall above is going to be waterproofed on the outside and has no earth contact on the inside, then I agree it has to be in the footing.

Cheers, Wayne

I agree. If the rebar is stubbed up and tied to the footing rebar than it isn't an issue. No different then when they stub up the rebar to connect to.

One argument could be that since the electrode is in the footing then the connection to the rebar must be accessible. I can't imagine why someone would call that...

 

[Dennis Alwon]

The problem is the inspector might say that he has no way of knowing if the rebar is tied together for 20' or more. Some guys can be difficult to deal with but IMO your install is fine.

 

[makemenuconfig]

Back to the OP, do you know if the footing was inspected and approved prior to the first pour?

We have a different AHJ for electrical than for the building side of things. So I presume the footing was inspected prior to pour, but I'm sure that inspector didn't care about the CEE.

But if the footing is cast directly against the earth, with no rebar stubbed out, and the wall above is going to be waterproofed on the outside and has no earth contact on the inside, then I agree it has to be in the footing.

This is a really good point, that the concrete makes contact with earth. I suppose the cold joint between footing and wall may just not be reliable/tested enough for a CEE in the wall to conduct through the bottom of the footing. In this particular scenario the wall pictured will not receive waterproofing because it is an interior wall and will be mostly buried. But I see how this may be non-standard enough for the inspector to be concerned.

 

[makemenuconfig]

Anyway, thanks all for weighing in!