What Are the Regulations for Fire Doors

- Apr 10, 2019-

Fire ratings measure the amount of time that a door is able to contain the spread of fire, as tested according to NFPA guidelines. This means a door with a two-hour rating, for example, can be expected to resist combustion for two hours in the event of a fire. Also, a fire door will typically have three-quarters of the rating of the surrounding wall. For instance, a wall with a two-hour rating will usually contain doors with a 90-minute rating. Overall, a fire rating can range from 20 minutes to three hours, but keep in mind that 20-minute doors are designed to block smoke rather than flames. The rating requirements for each type of door and wall in a building are set by a fire marshal or by building codes.

 

Door and Frame Requirements Wooden fire doors must have solid wood or mineral cores, while steel doors typically have honeycombed or insulated cores. The door should be prepped at the factory so there is no more than three-quarters of an inch of clearance between the bottom of the door and the finished floor. Also, no holes larger than 1 inch in diameter may be drilled without voiding the fire rating. Pairs of doors must be equipped with an astragal, or overlapping seam or molding. Additionally, frames must be made from at least 16-gauge steel and should be prepped at the factory to receive hardware.