Which component is described as a combination of a fire door, a frame, hardware, and other accessories installed in a horizontal plane to provide fire protection to a through-opening in a fire-resistance-rated floor?

• A. FireBarrier
• B. Thermal Barrier
• C. Floor Fire Door Assembly
• D. Building

Answer: (C)

Protecting through-openings in a fire-resistance-rated floor is accomplished by a floor fire door assembly. This term refers to the complete package installed in the floor opening: a fire door, its frame, hardware (closer, hinges, latches, etc.), and any accessories that ensure the opening remains fire-rated. The core idea is that the assembly sits in the floor (a horizontal plane) and when closed, seals the opening to resist fire and smoke transfer between floors for the specified duration.

Other terms describe different concepts: a FireBarrier is a fire-rated wall or partition, not a floor opening; a Thermal Barrier is a generic protection concept for materials but not a specific floor-assembly component; a Building is the entire structure, not an individual protective assembly. Thus the description points to the floor fire door assembly.