ICC Commercial Building Inspector Practice Test

What is the maximum fire door rating for which a 10" x 10" vision panel is permitted in a 2 hour fire wall?

1. 1 hour rated

2. 1-1/2 hour rated

3. 2 hour rated

4. 3 hour rated

The correct answer is: 1-1/2 hour rated

In the context of fire-rated assemblies, the permitted size of vision panels is influenced by the fire door's rating. For a 2 hour fire wall, the code allows specific configurations for openings that include vision panels based on the rating of the door. A 10" x 10" vision panel is permitted in a fire door rated for 1-1/2 hours, as this rating balances the need for life safety, smoke control, and operational integrity of the door. Fire doors are integral for preventing the spread of fire and smoke, and their design— including vision panels— is strictly regulated to maintain their effectiveness. As the fire door rating increases, the code typically imposes more stringent performance criteria, which can limit the size of any openings. Therefore, while a vision panel is permissible in a 2 hour fire wall, it is limited to being part of a door that is rated for 1-1/2 hours. This ensures that the integrity of the fire separation is not compromised, providing adequate protection against fire spread while still allowing for visibility through the door.