Maintaining a fire in the room of origin is critical in limiting the damage and associated losses. Fire doors are designed to protect openings in walls and elevator or stair enclosures against the spread of fire within buildings or from an external source. Fire doors are classified into one of the following categories:
- Metal Clad
- Passenger Elevator
- Rolling Steel
- Sheet Metal
- Sliding (hollow metal and composite)
- Special Purpose
- Swinging (hollow metal and composite)
All FM Approved fire doors are evaluated based on full-scale fire testing. Based on the results of these tests, each door receives a fire resistance rating (specified in hours) to indicate the acceptable duration of the fire exposure.
Fire doors can also be provided with a temperature transmission rating which provides the anticipated temperature rise developed on the unexposed surface of the door after 30 minutes of fire exposure.