Code Grounding Requirement Raising Questions
In a change from current building practices, reinforcement steel (rebar) in footings will be required by the 2005 edition of the National Electrical Code (NFPA) 70 Section 250.52(3) to be used as the primary grounding electrode for the electrical system.
With this change, 20 feet or more of rebar in the footing must be connected to the grounding electrode system.
If a metal water pipe serves the building, it also will need to be bonded to the system, although a ground rod will no longer be required.
The new requirement in the electrical code is raising a number of questions among builders, including:
- Does all of the rebar in the footing need to be used?
- Will a maximum of 20 feet comply with this provision?
The NAHB Codes and Standards staff is submitting a request for an official interpretation that should be available sometime this fall.
For more information, e-mail Larry Brown at NAHB, or call him at 800-368-5242 x8565.