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Fire Ratings
Fire doors and their respective frames and hardware are rated by the amount of time, in minutes or
hours, that a door can withstand fire in test conditions.
Laws and regulations can vary widely between states, cities, townships and
municipalities. Always be sure to check with all regulating authorities to
ensure the door units you order and install comply with all applicable laws.
Positive Pressure (UL10c) Fire Doors
The WDMA (Window and Door Manufacturers Association) separates positive pressure fire-rated
doors into two categories. Both Category “A” and Category “B” doors make use of intumescent seals.
These materials expand when heated, creating a tight seal and filling in gaps around the door. In test
conditions, this helps prevent the spread of fire and super-heated gasses from escaping.
Category “A”
Category “A” doors have intumescent seals and/or gasketing built into the structure of the door. They
typically do not require additional sealing between the door and frame but may require a smoke seal
or additional gaskets.
Category “B”
Category “B” doors are neutral pressure doors that require an additional intumescent strip
and/or gasket kit applied to the frame to provide an intumescent seal. These kits are available through
Reeb
®
and need to be applied according to the enclosed instructions by the installer in the field.
Because fire regulations can vary widely, some areas will also require an intumescent strip as part of
the door’s edge. Please be sure to specify all rating requirements to your Reeb sales representative.
Intumescent strip applied to
hollow metal frame by the
installer in the field
