Gap underneath fire door

[Guest Bradley]

Hello,

I’m a surveyor, I’ve been recently tasked with surveying a lot of doors in and around London and keep coming up against the same problem which is the bottom of the doors have a gap greater than 8mm, as this is not ideal my clients have been ordered to reduce the gap, before becoming a surveyor I was a carpenter with 22 years experience and have always cut and lipped (with hardwood) my own fire doors whether it be to reduce or in some cases extend the door, I am now being told that this is no longer the case, so my question is can we still cut and lip fire doors ?

Thanks

[Neil Ashdown MAFDI]

Yes you can reduce and lip fire doors. However, anything you do to a fire door must be within the scope of the door's product data sheet or technical manual so where you can find out which company made the door always refer to the data before carrying out any works.

Don't forget, if the fire doors are required to restrict spread of cold smoke (which is most of them) the threshold gap should be 3mm max or you should fit a threshold smoke seal.