For several years the City of Greenville has required that a Grounding Electrode be encased in concrete in the foundation system of a newly-constructed house. In addition to the expense of compliance, theft became a problem as thieves began stealing the 4 gauge copper wire that is fastened to the Grounding Electrode and left protruding from the foundation. Repairs include welding a new portion of wire to the remaining wire if practical, or encasing a new Grounding Electrode in a new section of concrete, in contact with the earth, where at least two inches of concrete covers the Grounding Electrode.
At your Home Builders Association's request, the city reviewed and modified this requirement.
Encasing the Grounding Electrode is now required only when rebar is embedded in the foundation. The code requires that rebar in a foundation be bonded to the earth. If rebar is not present in the foundation, a Grounding Electrode, or more than one when required by the code, may be driven into the earth.
When encasing the Grounding Electrode in the foundation is required, consider these options to protect against theft:
- Bury and mark the wire after inspection to deter theft.
- Install a galvanized or other rust-resistant Grounding Electrode so that a portion of the rod protrudes from the foundation, preferably facing the inside of the crawl space or basement, and mechanically fasten the wire later in order to deter theft. Remember however that at least 20 feet of continuous rod, ½-inch in diameter, must be encased by at least 2 inches of concrete. When more than one rod of shorter lengths is used, the rods must be properly connected.