UFER or EFER Ground requirements

[Coastalguy1]

I am looking for some clarification on the requirements of NEC Section 250.52(A)(3 regarding CEE or UFER grounding requirements for a new residential construction.
Concrete Encased Electrode. An electrode encased by at least 50 mm, (2inches) of concrete, located horizontally near the bottom or vertically, and within that portion of a concrete foundation or footingthat is in direct contact with the earth, consisting of at least 6.0 m (20 ft.)of one or more bare or zinc galvanized or other electrically conductive coatedsteel reinforcing bars of not less than 13mm (1/2 in) in diameter, orconsisting of at least 6.0 m (20ft.) of bare copper conductor not smaller than4 AWG. Reinforcing bars shall be permitted to be bonded together by the usualsteel tie wires or other effective means. Wheremultiple concrete encased electrodes are present at a building or structure, itshall be permissible to bond only one into the grounding electrode system.
I also looked at ICC 2009
E3608.1.2 Concrete-encased electrode. An electrode encased by at least 2 inches (51 mm) of concrete, located horizontally near the bottom or vertically and within that portion of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 20 feet (6096 mm) of one or more bare or zinc-galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than ¹/₂ inch (12.7 mm) diameter, or consisting of at least 20 feet (6096 mm) of bare copper conductor not smaller than 4 AWG shall be considered as a grounding electrode. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means. Where multiple concrete-encased electrodes are present at a building or structure, only one shall be required to be bonded into the grounding electrodes.

If this got missed during slab in construction is there another grounding method acceptable?:?

 

[rcarroll]

If there is #4 or larger, 20' minimum length rebar, in the footing, you must use it as a grounding electrode. No rebar no worries.

 

[petersonra]

If there is #4 or larger, 20' minimum length rebar, in the footing, you must use it as a grounding electrode. No rebar no worries.

unless it has a plastic vapor barrier under it in which case it does not qualify as a CEE.

my understanding is that normally the concrete guys leave an exposed piece of rebar to attach to in many locales. it might be covered up but it should not be real hard to get to if you know where it is.

the code now says you have to use all available grounding electrodes.

 

[GoldDigger]

...the code now says you have to use all available grounding electrodes.

The exception the OP quoted is still there in [2011]. Are you saying that there are local overrides or that the language changes in [2014]?

Where multiple concrete encased electrodes are present at a building or structure, it shall be permissible to bond only one into the grounding electrode system.

It is true that if there is one CEE, currently inaccessible or not, then you have to figure out a way to use it unless you can provide an alternate CEE.
In some cases it might actually be easier to find another CEE. You can at least choose the slab location that is easiest to attach to as long as it is within the same structure.

 

[Coastalguy1]

Thank you all for the replies. I checked with the local building official and he said a request for modification needs to be submitted for his review but it is a requirement.:thumbsup: