Ufer Ground & Ground Rods

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Danutdlp

Danutdlp

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Seattle, Washington
My friend is adding 1100 sq ft onto his older home, and since there will be a new footing poured for the addition and the service moved and upgraded, I am able to run a ufer ground in the foundation footing. Do I still need to drive in 2 ground rods?

Thanks:smile:
 
Havent read the code quite a while on this, but a few code cycles back you were able to utilize a full stick of #4 rebar incased in the concrete in leu of a actual ground rod.

Is this still compliant? and if it is, can the connection to the rebar be done
"in the concrete" instead of being accessible?
 
Ufer ground can be a 20 foot piece of #4 copper encased in concrete or a piece of rebar 20' in the concrete. The connection does have to be accessible. Normally the access is a 2 gang mud ring in the garage right where the connection is and a black cover put on.
 
one back to you

one back to you

yes, you can was a 20' #4 piece of rebar. And, you bend your piece of rebar up out of the footing and add a clamp and add a mud ring for access.
 
Mule said:
Havent read the code quite a while on this, but a few code cycles back you were able to utilize a full stick of #4 rebar incased in the concrete in leu of a actual ground rod.

Is this still compliant? and if it is, can the connection to the rebar be done
"in the concrete" instead of being accessible?
Click to expand...

Yes it is compliant per 250.52(A)(3), #4 copper to the CEE per 250.66(B), and it does not need to be accessible per 250.68(A) execption 1. 2005 NEC
 
I agree no need for accessibility. Think of the #4 tied to the rebard as an extension of the rebar tied together in the footing. There is no accessibility to those wires. Also the only issue would be using a ground clamp suitable for use in concrete. All the acorns I use are both suitable for db as well as encased in concrete.
 
Regarding clamps suitable for concrete encasement ...

The 2008 UL White book Section KDER (pg 180) informs that: ?Ground clamps and other connectors suitable for use where buried in earth or embedded in concrete are marked for such use. The marking may be abbreviated ??DB?? (for ??Direct Burial??). "

It seems if they are listed for direct burial and marked as such, they are lsited for concrete encasement as well...

mweaver
 
Danutdlp said:
Ufer ground can be a 20 foot piece of #4 copper encased in concrete or a piece of rebar 20' in the concrete. The connection does have to be accessible. Normally the access is a 2 gang mud ring in the garage right where the connection is and a black cover put on.
Click to expand...

B-inspector said:
yes, you can was a 20' #4 piece of rebar. And, you bend your piece of rebar up out of the footing and add a clamp and add a mud ring for access.
Click to expand...

jumper said:
Yes it is compliant per 250.52(A)(3), #4 copper to the CEE per 250.66(B), and it does not need to be accessible per 250.68(A) execption 1. 2005 NEC
Click to expand...

Dennis Alwon said:
I agree no need for accessibility. Think of the #4 tied to the rebard as an extension of the rebar tied together in the footing. There is no accessibility to those wires. Also the only issue would be using a ground clamp suitable for use in concrete. All the acorns I use are both suitable for db as well as encased in concrete.
Click to expand...

mweaver said:
Regarding clamps suitable for concrete encasement ...

The 2008 UL White book Section KDER (pg 180) informs that: ?Ground clamps and other connectors suitable for use where buried in earth or embedded in concrete are marked for such use. The marking may be abbreviated ??DB?? (for ??Direct Burial??). "

It seems if they are listed for direct burial and marked as such, they are lsited for concrete encasement as well...

mweaver
Click to expand...

During my time as an inspector, I started requiring these ufer grounds on new construction on the east side of town, which are plagued with lime stone rock. This side of town is typicaly imposible to drive a ground rod. Previous inspectors had allowed 6ft rods, which still often got sawed off short.

So I had them bend the rebar up through the footing. They are still doing this today, but they have started the access point via the mud ring and plate. To me, the ground rod clamp is no less accessible than a buried rod laid in a ditch. The only difference is the chemical reaction of the concrete to the connection components.
 
Mule said:
So I had them bend the rebar up through the footing. They are still doing this today, but they have started the access point via the mud ring and plate. To me, the ground rod clamp is no less accessible than a buried rod laid in a ditch. The only difference is the chemical reaction of the concrete to the connection components.
Click to expand...

It is fine to bend the rebar up and connect to that with a clamp, however if the clamp is suitable for being enclosed in concrete then I see no reason to turn the job down.

Personally, I have stated this before, I enclose 20 feet of #4 attached to the rebar in the footer. Heck if the clamp does fail I still have the 20 feet of #4.
 
Mule said:
During my time as an inspector, I started requiring these ufer grounds on new construction on the east side of town, which are plagued with lime stone rock. This side of town is typicaly imposible to drive a ground rod. Previous inspectors had allowed 6ft rods, which still often got sawed off short.
Click to expand...

Mule, did you have a local code that allowed you to "require" CEE's in new construction?
 
jumper said:
Gentleman, are we saying that the rebar needs to be 1/2" or larger, okay, or that the UFER needs to be be rebar, not okay, see Mr Alwon's post. I read this top statement both ways due to a minor grammatical error. Just trying to learn.
Click to expand...


To qualify as an electrode the rebar needs to be 1/2" or larger and comprised of one piece, or several tied pieces, of rebar equaling a minimum of 20' in length. You could make your own CEE by installing a 20' piece of #4 or larger bare copper conductor in the footing.
 
infinity said:
Mule, did you have a local code that allowed you to "require" CEE's in new construction?
Click to expand...

Pardon me, CEE ? Copper Electrode E? got me?

If your refering to to copper plates, we had no ammendments in that reguard, however I never seen anybody use one, nor did any of the supply house's carry them.

We chose to do it from rebar, mostly because the builders complained that we were causing the electrician to make an additional trip to the job to install the grounding mean....So I said, OK, I'll allow the builder to install the piece of rebar since its really not electrical material, and the electricians can tie to it later. So I would just inspect the rebar piece at the footing inspection....that worked for everybody...
 
Concrete Encased Electrode

Concrete Encased Electrode

The 2005 NEC, section 250.50 states "All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system." The exception says that it is not required for existing buildings. So on new construction, if reinforcing steel is installed in the concrete, it must be used as part of your grounding electrode system. If the structural engineer happens to spec out plain concrete (not likely), then this would be a non-issue.
 
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