Waterproof ufer connection?

Merry Christmas

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
Since my Ufer connection is going to be under earth, should I waterproof (tar, silicone, etc.) the acorn nut connection ?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Why would a GEC connection to the CEE be "under earth"? The connection should be in the concrete or on a piece of rebar stubbed out of the concrete by not in contact with the earth.
 

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
The rebar stub is connected to the rebar grid, encased in concrete. The #4 bare copper is acorn nutted to the rebar stub, and will, in a day or two, be back-filled over with dirt. Thus the connection is under ground.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The rebar stub is connected to the rebar grid, encased in concrete. The #4 bare copper is acorn nutted to the rebar stub, and will, in a day or two, be back-filled over with dirt. Thus the connection is under ground.
I've never seen rebar in a footing that is permitted to be in contact with dirt because it will corrode in a short period of time. The GEC should connect within the concrete.
 

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
Over here, (NY), that’s how it’s done. In fact, I was going to just sink 2 ground bars into the earth but was told that with new construction you must do the CEE /Ufer way.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I've never seen rebar in a footing that is permitted to be in contact with dirt because it will corrode in a short period of time. The GEC should connect within the concrete.
I agree. Rebar is not listed for being buried in the dirt whether it is done that way or not in your area. It will corrode and you will lose that connection. Now if you can somehow protect the entire rebar then it may be fine..... Silicone the entire part that is stubbed out....
 

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
Well that’s what I want to do. I want to waterproof the entire 1 foot stub sticking out of the footing. I can slather tar on it and it will last forever. I just need to wait until the inspection is done so the inspector can see the connection. That’s what I’ll do I’ll just wait.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The building code would likely prohibit rebar in a footing from being in contact with the earth but the NEC seems to allow it when there is corrosion protection. Why can't the GEC be attached within the concrete?

250.68(C)(3)
A rebar-type concrete-encased electrode installed in accordance with 250.52(A)(3) with an additional rebar section extended from its location within the concrete to an accessible location that is not subject to corrosion shall be permitted for connection of grounding electrode conductors and bonding jumpers. The rebar extension shall not be exposed to contact with the earth without corrosion protection.
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
Rebar should not be in contact with soil, it needs to be encased in concrete to protect it from corrosion. So I suggest getting a length of 8" Sonotube that is 3" taller than the rebar stub, centering it over the rebar, and filling it with concrete.

Cheers, Wayne
 

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
Rebar should not be in contact with soil, it needs to be encased in concrete to protect it from corrosion. So I suggest getting a length of 8" Sonotube that is 3" taller than the rebar stub, centering it over the rebar, and filling it with concrete.

Cheers, Wayne
That is another good option. I will take it under advisement.
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
We have allowed the use of 250.68(C)(3) as an alternative to connecting the CEE to the GEC directly in the footing, but it has always been stubbed up through the wall (similar to a hold-down or anchor-bolt) which then gives the electrician a place to connect too later, and in those scenario's it either needs to be accessible (junction box) or the connection needs to be non-removable/irreversible. I have never seen what you're describing.
Rebar should not be in contact with soil, it needs to be encased in concrete to protect it from corrosion. So I suggest getting a length of 8" Sonotube that is 3" taller than the rebar stub, centering it over the rebar, and filling it with concrete.

Cheers, Wayne
I like this solution given the scenario you describe.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
Well that’s what I want to do. I want to waterproof the entire 1 foot stub sticking out of the footing. I can slather tar on it and it will last forever. I just need to wait until the inspection is done so the inspector can see the connection. That’s what I’ll do I’ll just wait.
Wait… if your an inspector you should know rebar isn’t allowed to stick out of the concrete…
rebar is required to have concrete cover by ACI 318
Why didnt the rebar come up beside a column?
 

Fmkehoe

Senior Member
Location
Cornwall ny USA
Occupation
Inspector
Wait… if your an inspector you should know rebar isn’t allowed to stick out of the concrete…
rebar is required to have concrete cover by ACI 318
Why didnt the rebar come up beside a column?
I’m not an inspector. Not an electrical inspector anyway. That’s why I’m asking. I’ll just wait for the inspector to come and tell me. I won’t have that section back-filled.
 
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