Ive never ran into this situation. I am wiring a home, and the foundation is totally waterproof. Not touching the ground. there is steel rods that go 20 ft into the ground that tie to the foundation, but the foundation itself doesnt touch the ground. Do I have to have a concrete encased electrode? What would meet the code for the grounding electrode system? Thanks in advance
water sealed concrete- encased Electrode
- Thread starter JEI
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- Placerville, CA, USA
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- Retired PV System Designer
If there is no earth contact (that is not only the basement floor but all concrete down to the bottom of the footings and any piers is separated by a waterproof insulating membrane) then you do not have a ufer ground. You can confirm this if you want by doing a ground resistance measurement from piece of rebar, but that will not change the fact that the code requires direct earth contact:
250.52(A)(3)
Even non-waterproof insulation, such as the integrated insulation foam forms (ICF) for pouring concrete, or slabs of insulating foam under the floor are considered to prevent direct earth contact.
The bad news is that it does not count toward the ground electrode requirement. The good news is that you do not have to bond to it.
ceb58
Senior Member
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- Raeford, NC
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
I know many slab houses can't be used for a CEE if is has a vapor barriers or insulation foam boards under it, but if there are footers that go down to the frost line like we have to have around here and they are poured concrete then it can be used if it has 20' of re-bar or copper wire in it located close to the bottom of the concrete, these footers are rarely vapor blocked or would have foam insulation board under them, I know in Florida most houses were slab and didn't have footers so many times we couldn't use the slab as a CEE.
In the case where you can't use the slab then you just install rods to either supplements the water line or if the water line is plastic then you might end up to only having the rods as your electrode system very common around here on houses with wells, Indiana still doesn't require a CEE if it wasn't made available before we get there, but I always try to set it up with the builder so it can be.
We were required to use CEE's in Florida even back in the 70's because of the lightning down there.
In the case where you can't use the slab then you just install rods to either supplements the water line or if the water line is plastic then you might end up to only having the rods as your electrode system very common around here on houses with wells, Indiana still doesn't require a CEE if it wasn't made available before we get there, but I always try to set it up with the builder so it can be.
We were required to use CEE's in Florida even back in the 70's because of the lightning down there.
kwired
Electron manager
- Location
- NE Nebraska
NEC does not require us to use a CEE, it requires us to connect to a CEE if one is present. If your footings are insulated from earth they are not qualifying CEE's and do not need to be connected to the electrical system. You can make a CEE if you want, but you are only required to use one if it is present.
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