Grounding electrode connections and the 5 ft rule

What the code requires

Every mechanical connection that attaches a grounding electrode conductor or bonding jumper to an electrode must be accessible. Jumpers must bridge insulated joints and any equipment likely to be removed, such as water meters and filters, and be long enough that the equipment can come out without breaking the bond.

Interior metal water pipe may be used to extend the grounding connection to an electrode only within 5 ft of the point where the pipe enters the building, measured along the piping. Beyond that point, water pipe may not be used to interconnect electrodes.

A building's structural steel frame may interconnect electrodes or serve as the grounding electrode conductor, and hold-down bolts may connect it to a concrete-encased electrode. A rebar extension may be brought out of the concrete to an accessible spot that will not corrode, but it may not touch the earth without corrosion protection, and rebar may not interconnect electrodes.

On the job

• A grounding electrode conductor clamped to interior water pipe more than 5 ft of pipe from where the pipe enters the building is a common correction. The water pipe bonding rules in 250.104 are a separate requirement.
• Clamps hidden behind drywall or otherwise inaccessible get flagged.
• A missing jumper around a water meter or filter is another frequent fail.

Exceptions that matter

• Connections that are encased or buried with a concrete-encased, driven or buried electrode do not have to be accessible.
• Exothermic or irreversible compression connections to fireproofed structural metal do not have to be accessible.
• Commercial, industrial and institutional buildings with qualified maintenance staff and exposed piping may use water pipe beyond 5 ft.

What changed in 2023

The 2023 edition made clear that the 5 ft limit is measured along the length of the water piping.

Related sections

• NEC 250.52: What counts as a grounding electrode
• NEC 250.53(D)
• NEC 250.64
• NEC 250.70
• NEC 250.104: Bonding water pipes, gas pipes and structural steel

Where this comes from

• NFPA: 2023-cycle CMP-5 First Draft ballot (FR 8157)
• NFPA: 2026-cycle CMP-5 First Draft ballot (draft Article 252, repeating 2023 Article 250 text)
• Mike Holt: Summary of the 2023 Changes to the NEC
• EEPower, NEC 2023 Basics: Grounding and Bonding Piping Systems and Exposed Structural Metal
• Read the official NEC free at NFPA