Electrical work contracted under C K ELECTRIC · CSLB Lic. #354550 (C-10) · Farmer Works Electric license in process
(949) 702-0385
ServicesEV chargersFree toolsCode libraryWorkService areasAboutContact
Call (949) 702-0385Text a photo

Electrical work contracted under C K ELECTRIC · CSLB Lic. #354550 (C-10) · Farmer Works Electric license in process

NEC 300.11 · Homes and commercial

Supporting wiring above suspended ceilings

Wiring above a drop ceiling generally may not be supported by the ceiling grid or the ceiling's own support wires. Added independent support wires secured at both ends may be used. Cables may not support other cables.

Cross-section of a drop ceiling: wiring tied to ceiling wires, laid on the grid or strapped to EMT is not allowed; independent marked support wires are.
The ceiling wires and grid hold up the ceiling; wiring above it gets its own support wires, secured at both ends and easy to tell apart. Diagram: Farmer Works Electric, free to share under CC BY 4.0 · Download PNG · How to credit

What the code requires

Above a suspended ceiling, ceiling support wires that do not give secure support may not be the only support for cables, raceways or boxes. Independent support wires added with fittings may be used if they are secured at both ends. No cable or raceway may be supported by the ceiling grid itself.

In a fire-rated ceiling assembly, wiring in the cavity may not be fastened to the ceiling assembly or its support wires. Independent supports may attach to the assembly, and the added support wires must be distinguishable from the rated design, for example by color or tagging. Non-fire-rated ceilings follow the same rules, and the added wires must also be distinguishable.

A raceway may support other items only if it is identified for support, if it carries power to equipment and supports that equipment's Class 2 or Class 3 control wiring, or if it supports boxes or conduit bodies under 314.23 or luminaires under 410.36(E). Cables may not support other cables, raceways or nonelectrical equipment.

On the job

  • MC cable or raceway tied to ceiling grid wires or T-bar is a common correction.
  • Data cable strapped to an EMT run is a common fail.
Parallel runs of metal EMT conduit bending into a pull box on a wall
EMT conduit runs into a pull box (representative stock photo).

Exceptions that matter

  • In fire-rated ceilings, assemblies that were tested with the wiring in place are an exception.
  • In non-fire-rated ceilings, the ceiling system may support branch-circuit wiring if the ceiling manufacturer's instructions allow it.

What changed in 2023

The 2023 edition added Class 3 control wiring to what a raceway carrying power to equipment may support.

Related sections

Where this comes from

0/300

Answers come from this library only and are written by AI. They can be wrong, so check the cited section and confirm with your building department.

San Clemente · South OC to North County San Diego

Send a photo. Get a real answer.

Text is fastest, and a photo quote is free. Call if it is urgent, if you smell something burning, or if a breaker will not reset.

Call Shane· (949) 702-0385Text Shane a photo

Electrical work contracted under C K ELECTRIC · CSLB Lic. #354550 (C-10) · Farmer Works Electric license in process