Waterproof ufer connection?

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Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
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.
What do you inspect? Just out of curiosity...
 

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
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.
I think your mistaken or mis informed. Nothing in code says you must use an ufer, it is just an option. As already stated the connection point of the GEC to the electrodes has to be accessible. The concrete that ufer must be encase in itself shall not be insulated or or waterproof membrane applied. Most times around here this precludes the use of an ufer. Better read up on 250
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I think your mistaken or mis informed. Nothing in code says you must use an ufer, it is just an option. As already stated the connection point of the GEC to the electrodes has to be accessible. The concrete that ufer must be encase in itself shall not be insulated or or waterproof membrane applied. Most times around here this precludes the use of an ufer. Better read up on 250
A CEE must be used if the rebar in the footing qualifies as an electrode. That would be any rebar that is in a footing in contact with the earth and has rebar 1/2" or larger and 20' or longer. If the rebar in the footing does not qualify as an electrode or there isn't any then as you've said it's optional.
 

Joe.B

Senior Member
Location
Myrtletown Ca
Occupation
Building Inspector
I think your mistaken or mis informed. Nothing in code says you must use an ufer, it is just an option. As already stated the connection point of the GEC to the electrodes has to be accessible. The concrete that ufer must be encase in itself shall not be insulated or or waterproof membrane applied. Most times around here this precludes the use of an ufer. Better read up on 250
250.50 All grounding electrodes as described...shall be bonded together... Exception: CEE's of existing buildings...

If you have an existing foundation then code does not require the CEE. New construction will require it in most circumstances.
A CEE must be used if the rebar in the footing qualifies as an electrode. That would be any rebar that is in a footing in contact with the earth and has rebar 1/2" or larger and 20' or longer. If the rebar in the footing does not qualify as an electrode or there isn't any then as you've said it's optional.
Infinity is spot on, in my opinion.
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
And, often frustratingly, qualifying rebar must be used as a CEE even if concrete was poured over it before you could connect.

P.S. But if you have multiple potential CEEs, I believe you only need to connect to one of them.
 
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WSG

MN elec contractor
Location
Minnesota
Occupation
Electrician & Contracor
Since my Ufer connection is going to be under earth, should I waterproof (tar, silicone, etc.) the acorn nut connection ?
Looking at NEC 2020, 250.52(3)(2) ...

The CEE can be 20ft minimum of 4 AWG bare copper. Then you don't have to have any connection to the rebar
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
Looking at NEC 2020, 250.52(3)(2) ...

The CEE can be 20ft minimum of 4 AWG bare copper. Then you don't have to have any connection to the rebar
That is correct, you can use either the rebar or 20' of bare #4 or large copper wire. They are not required to be connected together.
 

shortcircuit2

Senior Member
Location
South of Bawstin
Since my Ufer connection is going to be under earth, should I waterproof (tar, silicone, etc.) the acorn nut connection ?
Read 250.68(C)(3)b. on page 124 of the 2020 NEC as the rebar extension can not be exposed to contact with the earth. (unless corrosion protection is provided)...

Why? The rebar is steel and it will corrode away in time.
 

kwired

Electron manager
Location
NE Nebraska
common for some the concrete guys around here, when there is a basement or other slab involved anyway, to bend a piece of rebar to stick out the footing and into where slab will be poured in the future at a point near where electrical service is to be located.

Then the electrician don't have to be there to attach to it at the time footing is poured but can come sometime before slab is poured to attach a conductor to it, and the attachment still ends up in concrete. Or it can be stubbed above the slab for later attachment, but must remain accessible in that case.
 
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