What Are Fire-Resistance Ratings in Access Panels?

A fire-resistance rating, like 1-hour and 3-hour fire ratings, refers to an access panel's certified performance in a fire. This rating is determined through rigorous, standardized fire tests conducted by organizations like Underwriters Laboratories (UL).

Fire resistance tests evaluate a panel's ability to serve as a component of a fire-rated assembly, such as a wall or ceiling. A fire-resistance rating is based on two key performance metrics:

• Structural Integrity: This measures how long the access panel can prevent the spread of flames. The panel must remain intact for the set period and not crack, warp, or collapse to allow fire to pass through.
• Thermal Insulation Standards: This measures the panel's ability to limit heat transfer. The temperature on the side of the panel not exposed to fire must remain below a certain threshold for the test duration.

It is important to understand that a panel's rating is tied to the specific test it passed.

For instance, a panel listed for a 1-hour wall assembly cannot be used in a 1-hour ceiling assembly. Similarly, you can’t put a 1-hour rated panel into a 2-hour rated wall and expect it to pass.

A fire-rated access door is an important part of the fire barrier where it's installed, and its failure compromises the entire system.