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.
10 mm gap under fire door.
Nothing must be cut at the top at all and the certification label must remain intact.
Doors with a horizontal cross bar meet the requirements for separating elements in fire rating classes e30 ei15 and a30.
The gap between the door and the frame is extremely important and must be suitable for the intumescent seal fitted.
In general the gap should not exceed 3 mm.
When speaking with manufacturers however a common statement is that a fire doors gap of up to 8 mm underneath the door is permissible.
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.
Contains information on maximum gap allowances for different types of fire doors.
1 8 meeting edges for a pair of doors.
Under the bottom of a door.
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.
How much can you cut off a fire door.
1 8 for more detailed gap information refer to nfpa 80 section 6 3 1 7 and section.
Thresholds are available in various versions the doors can also be installed without a threshold with a 10 mm gap under the bottom edge.
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.
Bs 8214 2008 code of practice for fire door assemblies states that 9 5 3 under door threshold gaps.
Our fire door gap gauge is a handy tool designed for easy use thanks to the clearly marked dark blue recommended door gap area.
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.
Nfpa 80 fire doors and other opening protectives.
3 4 between door and frame.
In general clearance for those allowed gaps are as follows.
Fire door seals august 2012 bw623 gap tester outlines indd 2 20 10 10 11 24 31 giving you the facts about fire door seals.