CEE and NEC

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ivsenroute

ivsenroute

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Florida
I am having a difference of opinion that I would like to have clarified or debated here.

I think the following is acceptable.

A 20' piece of proper rebar (5/8" bare steel) is being used as a CEE. The last 18" come out the top of the footer and will be bent downward and encased in concrete when the basement floor is poured. The electrical inspector was present for the footing pour to verify the proper installation of the rebar.

A properly sized GEC is attached to the end of the rebar in question with a clamp that is listed and labeled for attachment to rebar and for both DB and concrete encasement.

Would this be a compliant installation?
 
ivsenroute said:
A 20' piece of proper rebar (5/8" bare steel) is being used as a CEE. The last 18" come out the top of the footer and will be bent downward and encased in concrete when the basement floor is poured. The electrical inspector was present for the footing pour to verify the proper installation of the rebar.

A properly sized GEC is attached to the end of the rebar in question with a clamp that is listed and labeled for attachment to rebar and for both DB and concrete encasement.
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It sounds like a good work in progress.
It is > 1/2", bare steel, correct GEC, good connection.
It is not yet concrete consisting of 20' of encased rebar, but it will be.

If there is any problem I'd wonder about " . . . or vertically, and within that portion of a concrete foundation that is in direct contact with the earth, consisting of at least 6.0 m (20 ft) of one or more . . .". 250.52(A)(3).

Does the portion of concrete directly encasing the rebar need to be in direct contact with earth? Will the basement floor be in direct contact, or is there a vapor barrier? Would gravel be acceptable? The last two feet of rebar will be encased, the concrete will be in direct contact, is any offset in the length allowed?
 
Here the floors are usually a 4" pour. Even if the rebar was dead center of the pour, you would not have the required 2' encasement.
 
ivsenroute said:
I am having a difference of opinion that I would like to have clarified or debated here.

I think the following is acceptable.


Would this be a compliant installation?
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Tough luck on it being clarified - the concept of connections on/to stubbed up rebar has been debated to death at least once - so it depends on who you talk to.

IMO it is compliant! (whether the inspector saw it before the pour or not....)
 
IMO since you said that the last 18" came out of the footer then is does not comply with the 20' requirement even though it's still encased in concrete in the slab.
 
ivsenroute said:
Would this be a compliant installation?
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Some good points made against it complying with 250.52(A)(3) - it won't be encased if in a 4 inch floor especially.

If it does not comply, then it is not an electrode.

If it is not an electrode, it does not need to be used, 250.50. I believe it still could be left connected in that case, but not used as a supplement to a water pipe, or as the only electrode.
 
Ok, now who would be upset if an inspector failed them for this situation?

In the grand scheme of things, how important for safety and to what degree will that 18" affect the GE system if ever called upon to be used.
 
ivsenroute said:
Ok, now who would be upset if an inspector failed them for this situation?

In the grand scheme of things, how important for safety and to what degree will that 18" affect the GE system if ever called upon to be used.
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Well, the minimum is 20' of 1/2" rebar. By using 18.5' of 5/8" you've likely surpassed the amount of surface area in the concrete that the 20' of 1/2" would use. But it still doesn't comply with the written wording of the code. Just tie wire a 2' piece to the 18.5' and you're good.
 
infinity said:
Well, the minimum is 20' of 1/2" rebar. By using 18.5' of 5/8" you've likely surpassed the amount of surface area in the concrete that the 20' of 1/2" would use. But it still doesn't comply with the written wording of the code. Just tie wire a 2' piece to the 18.5' and you're good.
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It sounds like you are in the thinking that this one and only piece of rebar mentioned was the ONLY piece in the whole footing - tie wiring to any of those other pieces in the footing at the bottom and you get all of them - even if it is 10ea. 2' pieces. The medium we work with takes all paths..... In this case the steel is just a means of connection to the concrete and the concrete the connection to earth. The average footing is made up of a cage consisting of runners (long pieces) and a ladder of smaller pieces to join them together - all tie wired in the usual manner. Whether you like/approve of each one of them or not - they all act as your electrode - just as much as all of the concrete.
 
Just dig a little 18" haunch The same depth as the footing where the floor meets a couple of extra inches deep and snap a picture or two. Now the cee is fully encased for 20' . Everyone is happy. Keep the rebar below 2".
 
e57 said:
It sounds like you are in the thinking that this one and only piece of rebar mentioned was the ONLY piece in the whole footing - tie wiring to any of those other pieces in the footing at the bottom and you get all of them - even if it is 10ea. 2' pieces. The medium we work with takes all paths..... In this case the steel is just a means of connection to the concrete and the concrete the connection to earth. The average footing is made up of a cage consisting of runners (long pieces) and a ladder of smaller pieces to join them together - all tie wired in the usual manner. Whether you like/approve of each one of them or not - they all act as your electrode - just as much as all of the concrete.
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I wasn't thikning that at all. He stated the he had only 18.5' of rebar in the footing.

A 20' piece of proper rebar (5/8" bare steel) is being used as a CEE. The last 18" come out the top of the footer and will be bent downward and encased in concrete when the basement floor is poured. The electrical inspector was present for the footing pour to verify the proper installation of the rebar
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and,.. And I hate to bring it up,.. but the rebar is being used as the elctrode conductor .. I know no big deal .. just a thought.
 
M. D. said:
and,.. And I hate to bring it up,.. but the rebar is being used as the elctrode conductor .. I know no big deal .. just a thought.
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How so? It is an extention of it - much the way a water pipe sticking up to 5' out of the ground is not a GEC. Or the end a rod sticking up - so long as 8' are in the earth. Or if you had a 30' piece of #4 copper in the footing alone and stubbed some of it up.
 
M. D. said:
I found this a while ago ,.I think it is a good document ,.. even though they do not , as many others also do not, share my concern about the rebar being a grounding electrode conductor .. image #3


http://www.nh.gov/safety/divisions/...ocuments/050909_concreteencasedelectrodes.pdf
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The one thing I like really like about that document is the general statement of not being all inclusive of design - and that other creative methods of skinning cats were allowed, and by using the "Influence of ingenuity" (page 4) the wording is encouraging not to just do as you were taught by your Uncle Jack - because there is of course no other way...
 
e57 said:
How so? It is an extention of it - much the way a water pipe sticking up to 5' out of the ground is not a GEC. Or the end a rod sticking up - so long as 8' are in the earth. Or if you had a 30' piece of #4 copper in the footing alone and stubbed some of it up.
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Well if that vert. rebar does not meet the requirement for an electrode then it is a piece of steel ,.. most of the foundation walls that I work around are not in direct contact with the earth..
 
According to 250.52(A)(3) you can bond the rebar with the tie wire, but it doesn't say anything about splicing the electrode. Here we take care of that problem with a local ordinance, where you have to install the #4 bare copper.

Now to answer you'r question, I don't know that I would get to twisted up about it.
 
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