When speaking with manufacturers however a common statement is that a fire doors gap of up to 8 mm underneath the door is permissible.
10 mm gap under fire door.
Under the bottom of a door.
Doors with a horizontal cross bar meet the requirements for separating elements in fire rating classes e30 ei15 and a30.
From what i can make out building regs part f is saying that with an mvhr system internal doors should have a total of 7600mm air flow gap the example they quote is for a standard size of 760 door the gap underneath would need to be 10mm.
To facilitate the checking of this gap on site the bwf certifire fire door and doorset scheme has produced a gap tester which can be.
Nothing must be cut at the top at all and the certification label must remain intact.
Thresholds are available in various versions the doors can also be installed without a threshold with a 10 mm gap under the bottom edge.
In general the gap should not exceed 3 mm.
Bs 8214 2008 code of practice for fire door assemblies states that 9 5 3 under door threshold gaps.
The doors can be designed with anti finger trap.
3 4 between door and frame.
In general clearance for those allowed gaps are as follows.
How much can you cut off a fire door.
The gap between the door and the frame is extremely important and must be suitable for the intumescent seal fitted.
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.
1 8 for more detailed gap information refer to nfpa 80 section 6 3 1 7 and section.
1 8 meeting edges for a pair of doors.
Contains information on maximum gap allowances for different types of fire doors.
The gaps between a fire door and its frame need to be 2 to 4mm in width to ensure that both the door can close smoothly and that the fire cannot spread through the gap of the fire door.
Our fire door gap gauge is a handy tool designed for easy use thanks to the clearly marked dark blue recommended door gap area.
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 tester is available on request here.
Nfpa 80 fire doors and other opening protectives.