Many red tags are issued by city inspectors for conduits, electrical boxes, or luminaires incorrectly installed in fire rated walls, floors or ceilings.

The rules for installing electrical boxes, conduits, and luminaires in fire rated horizontal assemblies are not found in the NEC^®. The NEC^® simply requires the electrical installation to be made so that the possible spread of fire or products of combustion will not be substantially increased. This is accomplished when the electrician installs electrical boxes, conduits, and luminaires in compliance with the building code requirements for rated construction and follows the rules specified for such items that penetrate fore rated assemblies.

IBC Section 714 covers the materials and methods of construction used to protect through penetrations and membrane penetrations of horizontal assemblies and fire-resistance-rated wall assemblies.

Section 714.5 has subsections on membrane penetrations and through penetrations into horizontal assemblies. Fire resistance-rated horizontal assemblies include floors, floor/ceiling assemblies, and the ceiling membrane of a roof/ceiling assembly.

A through penetration is a breach in both sides of a floor, floor-ceiling or wall assembly to accommodate an item passing through the breaches. When an electrician makes a through penetration in a horizontal assembly, such as drilling holes to install raceways or conduits vertically between floors, the exceptions to the rules in IBC 714.5.1 must be followed.

A membrane penetration is a breach in one side of a floor-ceiling, roof-ceiling or wall assembly to accommodate an item installed into or passing through the breach. When an electrician makes a membrane penetration in a horizontal assembly, such as installing an electrical box or a recessed luminaire (light fixture) into a rated ceiling, the exceptions to the rules in IBC 714.5.2 must be followed.

Always be aware of the location of any fire rated walls or horizontal assemblies in the building.

When installing recessed lights into the ceiling of a rated horizontal assembly, IBC Section 714.5.2 exception 8 requires the luminaires to be listed and tested for use in fire-resistance-rated assemblies, or to use listed materials to protect the luminaire from compromising the membrane penetration into the rated horizontal assembly.

Likewise, NEC^® 410.116(C) requires the following:

NEC 410.116(C) Installation in Fire-Resistant Construction.

Luminaires marked “FOR USE IN NON-FIRE-RATED INSTALLATIONS” shall not be used in fire-rated installations. Where a luminaire is recessed in fire-resistant material in a building of fire-resistant construction, the recessed luminaire shall satisfy one of the following:

1. The recessed luminaire shall be listed for use in a fire resistance–rated construction.
2. The recessed luminaire shall be installed in or used with a luminaire enclosure that is listed for use in a fire resistance–rated construction.
3. The recessed luminaire shall be listed and shall be instal⁠led in accordance with a tested fire resistance–rated assembly. When a tested fire resistance–rated assembly allows the installation of a recessed fluorescent luminaire, a recessed LED luminaire of comparable construction shall be permitted.