Electrical wiring within a fire-rated floor-ceiling or roof-ceiling assembly shall not be supported by the ceiling assembly or ceiling support wires. Is this statement true or false?

The statement is true. In fire-rated floor-ceiling and roof-ceiling assemblies, it's critical to maintain the integrity of the fire-resistance rating of these structures. When electrical wiring is supported by the ceiling assembly or its support wires, it can compromise the assembly's ability to resist the spread of fire and maintain structural integrity during a fire event.

Supporting wiring from the ceiling assembly could lead to additional weight and stress that might disrupt the assembly, particularly if the fire puts the structure at risk. Therefore, codes and standards specify that electrical wiring must be independently supported, rather than relying on the ceiling or its components. This ensures that the fire-rated assembly can perform as designed, protecting occupants and limiting the spread of fire through the building.