This section has been amended at the state or city level.
Floor assemblies that are not required elsewhere in this code to be fire-resistance rated shall be provided with a 1/2-inch (12.7 mm) gypsum wallboard membrane, 5/8-inch (16 mm) wood structural panel membrane, or equivalent on the underside of the floor framing member. Penetrations or openings for ducts, vents, electrical outlets, lighting, devices, luminaires, wires, speakers, drainage, piping and similar openings or penetrations shall be permitted.
- Floor assemblies located directly over a space protected by an approved automatic sprinkler system.
- Floor assemblies located directly over a crawl space not intended for storage or fuel-fired appliances.
- Portions of floor assemblies shall be permitted to be unprotected where the aggregate area of the unprotected portions does not exceed 80 square feet (7.4 m2) per story.
- Wood floor assemblies using dimension lumber or structural composite lumber equal to or greater than 2-inch by 10-inch (50.8 mm by 254 mm) nominal dimension, or other approved floor assemblies demonstrating equivalent fire performance.