What is the relationship between a door rating and the door assembly rating?

• A. The door rating reflects the assembly's fire-resistance capability, applicable to the door, frame, and hardware tested together.
• B. The door rating is independent of the door assembly and refers to a single component.
• C. The door rating only applies to the door leaf, not frame or hardware.
• D. The door rating is determined by the weakest component in the system, not the assembly as a whole.

Answer: (A)

The key idea is that a fire rating is for the entire door assembly as it was tested, not just the door leaf. When doors are tested for fire resistance, the test includes the leaf, the frame, hardware, seals, and how they work together. The rating describes how well that complete assembly performs during the standard fire test, so it applies to the whole system that was evaluated—not to a single component in isolation. If you change components like the frame or hardware, you’d typically need to re-test the assembly to obtain a new rating. The other ideas—rating the leaf alone, rating being independent of the assembly, or being dictated by the weakest component—don’t reflect how fire-tested assemblies are determined.