Maximum Gap For Fire Door Thresholds

Current model codes call for some doors to have a maximum air leakage rate of 3 0 cubic feet per minute per square foot 0 015424 m3 s m2 of door opening at 0 10 inch 24 9 pa of water for both the ambient temperature test and the elevated temperature exposure test.

Maximum gap for fire door thresholds.

Contains information on maximum gap allowances for different types of fire doors. When speaking with manufacturers however a common statement is that a fire doors gap of up to 8 mm underneath the door is permissible. Frames used in masonry walls may be used with a maximum 3. There is negative pressure at the threshold during test conditions and so cool air is drawn in underneath the door.

Thresholds and saddles like other fire door assembly compo nents thresholds and saddles need to be installed in accordance with their in stallation instructions. In many cases the installation instructions require a maximum of 1 8 in. 1 8 for more detailed gap information refer to nfpa 80 section 6 3 1 7 and section. Under the bottom of a door.

I work in a relatively new office buiding that has internal fire doors with cold smoke seals and the gaps under the doors range from 5mm to 10mm. Clearance between the bottom of the door and the portion of the threshold directly under the door see. In general clearance for those allowed gaps are as follows. Mind the gap fire door seals fire doors play a crucial role in restricting the spread of fire and smoke.

It is through extensive testing of fire rated doorsets together with knowledge of the pressure regime within a fire test that a larger gap is permitted at the threshold of the door. What is the maximum you can have between the bottom of door and the thresholds for a fire rated door assembly i have some stairwell doors with 1 inch to 1 inch gap between the bottom of the door and the threshold. 3 4 between door and frame. Nfpa 80 fire doors and other opening protectives.

If a door is to work effectively in its normal role the door leaf must be free to move within the frame and in order to achieve this there must be a gap around the perimeter. Ings for a basic fire door frame unless the labeling on the frame specifically states that the frame is rated for something less than 3 hours. If a frame bears a recognized label qualifying it as a fire door frame it may sup port a 3 hour a 1 1 2 hour a 3 4 hour or a 1 3 hour door. 1 8 meeting edges for a pair of doors.