Stapling and supporting NM cable

What the code requires

NM cable must be secured with staples, cable ties listed for securement, straps, hangers or similar fittings that do not damage the cable. Fasteners can be no more than 4½ ft (1.4 m) apart.

The cable must be secured within 12 in. (300 mm) of every point where it enters a box, cabinet or fitting, and the cable between that entry and the nearest support may not be longer than 18 in. (450 mm). Flat cable may not be stapled on edge. Cable inside a protective raceway does not need to be secured within the raceway.

In runs that are not vertical, cable through holes or notches in framing counts as supported if those supports are no more than 4½ ft apart and the cable is fastened within 12 in. of each box or termination.

On the job

• A common correction is the first staple too far from the box. It must be within 12 in., and the cable from the box to that support no longer than 18 in.
• Over-driven staples that crush the cable jacket, and flat cable stapled on its edge, are also frequent corrections.

Exceptions that matter

• Cable may be unsupported where it is fished between access points through concealed spaces in finished buildings and supporting it is impracticable.
• In one-, two- and multifamily dwellings, cable may run unsupported up to 4½ ft from the last support to a luminaire or equipment in an accessible ceiling.
• For a device identified for use without a box, the cable must be secured within 12 in. of the wall opening, with a 12-in. loop or a 6-in. end left for future replacement.

Related sections

• NEC 300.4: Protecting cables from nails and screws
• NEC 314.17
• NEC 334.15: Protecting exposed NM cable

Where this comes from

• NFPA: 2026 NEC First Draft, CMP-6 (shows 2023 text of 334.30)
• Baltimore City Code: NEC Article 334 as adopted
• ExpertCE: Navigating NEC Article 334
• Read the official NEC free at NFPA