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Cross-market term

Fire door

A door assembly tested to hold back fire and smoke for a stated period. The rating belongs to the whole assembly — leaf, frame, seals, hinges and closer — not to the leaf alone.
  • 4Markets
  • NoSame thing everywhere
  • 3Calculators

What it is called, by market

One concept, four markets. Where a name means something else locally, the card says so rather than leaving you to find out on site.

  • United Kingdom

    Same word, different thing

    fire door

    also FD30, FD60, FD30S, notional fire door, fire resisting doorset

    The number is MINUTES OF INTEGRITY and the trailing S means smoke seals. A door marked FD30 without the S is not a smoke door, which is the distinction most often missed in a corridor.

  • Australia

    Same word, different thing

    fire door

    also FRL, -/60/30, fire door set, tagged door, smoke door

    FRL is THREE figures — structural adequacy / integrity / insulation — so a single number cannot express an Australian rating. A dash means that criterion is not required.

  • United Statesyours

    Same word, different thing

    fire door

    also 20-minute door, 90-minute door, labeled door, fire door assembly, positive pressure

    The rating is tied to the WALL the door sits in and to a listing label, and positive-pressure testing changed which assemblies qualify — so an unlabelled door has no rating regardless of construction.

  • Canada

    Close, not identical

    fire door

    also labelled door, fire protection rating, ULC label, closure

    CLOSURE is the code's own word covering doors, shutters and dampers together, and the rating is a FIRE PROTECTION rating, distinguished from the fire RESISTANCE rating of the wall.

The governing standard, by market

  • United Kingdom

    BS 476-22 / BS EN 1634-1

    Fire resistance tests for non-loadbearing elements including doorsets, and the European test method that increasingly replaces it.

  • United States

    NFPA 80 / UL 10C

    Fire doors and other opening protectives including installation and inspection, and the positive pressure fire test for door assemblies.

Calculators for this

Each works in either measurement system, and the terminology on the page follows whichever market you have selected.

Multi-Layer Fire-Rated (Type X) Gypsum Sheet Calculator →Fire-Rated Glazing Typical Edge Clearance Reference →ADA Door Maneuvering Clearance Calculator →

Frequently asked questions

Does a fire door rating apply to the door or to the whole assembly?
The assembly, and that is the single most consequential fact about them. What was tested was a complete doorset: a leaf of a particular construction, in a frame of a particular material, hung on particular hinges, with particular intumescent seals in particular grooves, closing with a particular device, in a wall of a particular type. Change any of those and the evidence no longer covers the installation. In practice that means the rating is lost by ordinary-looking decisions — fitting a letterplate, replacing broken hinges with whatever is in the van, planing the leaf to cure a sticking door, filling the gap between frame and structure with ordinary foam, or hanging a rated leaf in an unrated frame. Each looks like maintenance and each is a modification to a tested assembly. It is also why a fire door is inspected as an assembly, and why the gap around the leaf is measured rather than eyeballed.
What do the numbers in an Australian FRL mean, and why are there three?
They are three different failure modes, tested together and reported separately, because an element can fail one and pass the others. STRUCTURAL ADEQUACY is how long it keeps carrying its load — irrelevant for most doors, which is why the first figure is usually a dash. INTEGRITY is how long it stops flames and hot gases passing through, which is what a British FD number reports. INSULATION is how long the unexposed face stays cool enough not to ignite what is against it, and this is the one a single-number system does not tell you. A door can hold flame back for an hour while its own back face becomes hot enough to set light to a coat hanging on it, so a door rated -/60/30 is honest about lasting an hour against flame and half an hour before the far side becomes dangerous. Anyone reading an Australian specification with British habits will read the middle number and lose the third.
Why does the gap around a fire door matter so much?
Because the seals that close it only work over the range they were tested across. Intumescent strips swell when they get hot and fill the gap, and that expansion is finite: a gap of a few millimetres closes, a gap of twelve does not, and hot gas passes straight through a door whose leaf is intact. So the permitted gap is specified tightly at the head and stiles, and a larger one at the threshold is allowed only where the design accounts for it. The two failures this produces are opposite and equally common: a door planed to stop it binding, which opens the gap past what the seals can bridge; and a door fitted so tightly that the closer cannot latch it, so it sits ajar and has no rating at all because an unlatched fire door is an opening. That is also why the closer and the latch are part of the rated assembly rather than convenience hardware — a door that does not fully close and latch is not a fire door in any market.