It is NOT uncommon for doors to have a higher Fire Resistance Rating than the surrounding walls

It is NOT uncommon for doors to have a higher Fire Resistance Rating than the surrounding walls

• A. True
• B. False
• C. Not Applicable
• D. Sometimes

Answer: (B)

The strength of a fire-rated opening is limited by the weakest part of the opening. In a fire barrier, the wall sets the required protection, and the door in that opening must be at least that same rating. If the wall is rated for a certain duration, having a door with a higher rating doesn’t increase the overall protection, because the wall would still be the limiting factor and could fail sooner than the door. That’s why you don’t typically see doors with a higher fire-resistance rating than the surrounding walls; the overall assembly rating will be governed by the wall’s rating.

The strength of a fire-rated opening is limited by the weakest part of the opening. In a fire barrier, the wall sets the required protection, and the door in that opening must be at least that same rating. If the wall is rated for a certain duration, having a door with a higher rating doesn’t increase the overall protection, because the wall would still be the limiting factor and could fail sooner than the door. That’s why you don’t typically see doors with a higher fire-resistance rating than the surrounding walls; the overall assembly rating will be governed by the wall’s rating.