Direct answer
A fire door is a complete life-safety assembly
A fire-resisting doorset is designed to remain in an opening and limit the passage of fire for a defined test period. Where smoke control is required, the specification also addresses smoke leakage. The door supports protected escape routes and compartment boundaries; it is not intended to make an area permanently fireproof.
The relevant performance is established for a tested or assessed configuration. Changing the leaf, frame, glazing, seals, hinges, latch or closer without suitable evidence can alter that performance.
How it works
What makes a fire door work?
The leaf and frame form the main barrier. Hinges support the leaf; the latch helps retain it; the closer returns it to the shut position; seals respond to heat or restrict ambient smoke; and any glazing, letter plate or transfer grille must be compatible with the evidence for the assembly.
The surrounding wall and the joint between frame and wall are also important. A correctly specified doorset can still fail to deliver its intended protection if the opening, fixing or fire stopping is defective.
Leaf and frame
Provide the principal fire-resisting barrier and must be compatible.
Self-closing
Closes the door reliably from foreseeable open positions where required.
Seals and gaps
Control fire and, where specified, smoke within the permitted configuration.
Hardware and apertures
Must be suitable for the doorset evidence and its use.
Building context
Where are fire doors normally found?
Common locations include protected stairs and corridors, compartment walls, plant rooms, kitchens, service cupboards, flat entrances and routes between different uses. Not every door is a fire door, and similar-looking doors may require different performance.
Plans, fire strategies, door schedules, product evidence and the fire risk assessment can help establish each door’s intended role. Where evidence is missing, a competent survey may need to distinguish a confirmed defect from an unresolved performance question.
- Protected escape stairs and corridors
- Flat entrances and residential common parts
- Compartment and sub-compartment boundaries
- Higher-risk rooms, stores and plant spaces
- Mixed-use and landlord–tenant interfaces