What is the difference between an FD30 and an FD60 fire door?
The number is the minutes of fire resistance the doorset achieved under test: FD30 resists fire for 30 minutes, FD60 for 60. An S suffix, as in FD30S, means the doorset is also fitted with smoke seals and restricts cold smoke. Most flat entrance doors and internal corridor doors are specified FD30S, while FD60 turns up around plant rooms, some risers and wherever the building's fire strategy demands the longer period. The right rating comes from the fire risk assessment for the building, not from guesswork, and we will tell you plainly which one your opening needs.
Why does a fire door have to be fitted as a doorset?
Because the test that gave the door its rating was carried out on the whole assembly: leaf, frame, seals, hinges and closer together. Hang a certificated leaf in an old softwood lining with no intumescent protection and you no longer have a 30 minute door, you have an unknown. Wherever possible we install complete doorsets, and where a leaf is replaced into an existing frame we check the frame material and section against the door's certification first and say honestly if it will not comply.
What gap should there be around a fire door?
As a rule the gap between the leaf and the frame at the head and both stiles should be 2mm to 4mm, consistent along its length, with up to 8mm to 10mm at the threshold depending on the door's certification and whether a threshold seal is fitted. Gaps outside those tolerances let fire and smoke past the seals, and they are one of the most common failures found on inspection. Setting and correcting gaps is bread and butter work for us, on new installations and on doors already in service.
Do flat entrance doors have to be self-closing?
In a block of flats, yes. A flat entrance door that opens onto a common part must be self-closing, so it needs a controlled closer that shuts and latches the door from any open position. Under the Fire Safety (England) Regulations 2022, in residential buildings over 11 metres the responsible person must also carry out annual checks on flat entrance doors and quarterly checks on doors in common parts, which is exactly the routine our survey and maintenance work supports.
What are intumescent seals and smoke seals, and do I need both?
Intumescent seals are strips set into the door or frame that expand many times their size in the heat of a fire, sealing the gap between leaf and frame. Smoke seals are brushes or fins that block cold smoke from the first minutes of a fire, before there is heat enough to activate the intumescent. Smoke moves first and kills first, which is why most doors protecting escape routes are specified with both, usually as a combined strip. If your doors have intumescent only where the assessment calls for smoke sealing, that is a straightforward upgrade.
How do I know if my existing doors are certified fire doors?
Look at the top edge or hanging stile of the leaf for a coloured plug or a certification label; that marking ties the door to its test evidence. No plug or label does not automatically mean no fire door, but it does mean the rating cannot be demonstrated, which for a landlord or managing agent is much the same problem. A survey records each door's markings, condition, seals, gaps and ironmongery, and tells you door by door what can be kept, what can be brought up to standard and what needs replacing.
