Acceptable Gap Under Fire Door
Fire doors must be installed to as1905 1or as per tested or assessed which includes the allowable gaps around the stiles head and base of the door.
Acceptable gap under fire door. However for test purposes the threshold gap is taped and some form of effective threshold seal should be used if complete smoke control is to be achieved unless the threshold gap does not exceed 3 mm at any point. In general the gap should not exceed 3mm along the 2 long edges and across top of the door leaf to facilitate checking of the gap on site a bwf fire door alliance scheme gap. 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. Bs9999 2008 recommends for fire doors with cold smoke control that the threshold gap should be either less than 3mm in height or should be fitted with a threshold seal.
Also too large gap hinders reliable fixing of doors in the closed position. The old test of fire doors to bs 476 part 8 for fire resistance was carried out simply in a furnace increasing the temperature to that found in rooms on fire and the door was checked to ascertain when the fire would breach the door usually at the gaps at the head and sides of the door. 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. What gaps are required around a door and its frame.
Under the influence of moisture door can expand and then problems with its functionality cannot be avoided. It should be noted that when a 762 2 6 door leaf which is hung on standard hinges swings open the diagonal measurement of the leaf becomes effective and will reduce the clearance on the lock side by between 1 and 1 5 mm depending on the width and thickness of the door leaf. Mind the gap fire door seals fire doors play a crucial role in restricting the spread of fire and smoke. Bs 8214 2008 code of practice for fire door assemblies states that 9 5 3 under door threshold gaps.
Underneath the fire door a gap of 8mm is traditionally acceptable although for fire doors that are required to limit spread of cold smoke only 3 mm is permissible with a threshold seal to be fitted if the gap is bigger. Nothing must be cut at the top at all and the certification label must remain intact. The gap between the door and the frame is extremely important and must be suitable for the intumescent seal fitted. How much can you cut off a fire door.
Acceptable clearances stiles and head. The following technical sheet describes the maximum allowable gaps and acceptable rectification methods. In the closed position gaps between the door and. The development of fire door testing.