FIRE DOORSA fire door is a door with a fire-resistance rating (sometimes referred to as a fire protection rating for closures) used as part of a passive fire protection system to reduce the spread of fire and smoke.
|
|
Fire Ratings by Hour & by Letter-Designation:
Class "A" (3-hour)-Openings in firewalls that divide a single building into fire areas.
Class "B" (1 hour)-Openings in enclosures of vertical shafts and stairwells through buildings and in 2 hour rated partitions providing horizontal fire separations
Class "C" (3/4 hour) - Openings in walls or partitions between rooms and corridors having a fire resistance rating of 1 hour or less.
Class "D" (1 1/2 hour) - Openings in exterior walls subject to severe fire exposure from outside the building.
Class "E" (3/4 hour) - Openings in exterior walls subject to moderate or light fire exposure from the outside of the building.
No letter designation (1/2 or 1/3 hour) - Openings in walls or partitions between rooms and corridors having a fire resistance rating of 1 hour or less. Note that these doors are not really considered fire doors, but rather used for smoke control only.
Class "B" (1 hour)-Openings in enclosures of vertical shafts and stairwells through buildings and in 2 hour rated partitions providing horizontal fire separations
Class "C" (3/4 hour) - Openings in walls or partitions between rooms and corridors having a fire resistance rating of 1 hour or less.
Class "D" (1 1/2 hour) - Openings in exterior walls subject to severe fire exposure from outside the building.
Class "E" (3/4 hour) - Openings in exterior walls subject to moderate or light fire exposure from the outside of the building.
No letter designation (1/2 or 1/3 hour) - Openings in walls or partitions between rooms and corridors having a fire resistance rating of 1 hour or less. Note that these doors are not really considered fire doors, but rather used for smoke control only.
