Fire Doors Explained: FD30, FD60, Self-Closers & Gap Tolerances

01 · RatingsWhat FD30 and FD60 actually mean

An FD30 door is an assembly that has been tested and certified to maintain integrity, to stop fire passing from one side to the other, for at least thirty minutes. FD60 is the same test, sixty minutes. The number is a duration, not a material or a thickness. A door that is 54mm thick does not automatically have any particular rating; a door that is 44mm thick may perform to FD30 if the assembly has been tested to do so.

The rating is earned by a physical test. A full door assembly (leaf, frame, hinges, latch, closer, seals and any glazing) is installed in a test frame and exposed to a standard fire-temperature curve on one side. The test method is either BS 476-22:1987, the UK's long-standing fire-door test, or BS EN 1634-1:2014+A1:2018, the harmonised European method that now dominates new certification. Both are integrity-and-insulation tests under the E/I notation; for UK fire doors we usually only care about E (integrity). Cold-smoke control, where required, is tested separately under BS EN 1634-3 and the door then carries the 's' suffix, FD30s, FD60s.

Understand that the rating belongs to the assembly, not the door leaf alone. If a specifier or installer swaps the certified hinge for a hardware-store pack, removes the intumescent strip to "tidy up" the rebate, or replaces the closer with an uncertified model, the leaf is still the leaf, but the assembly no longer has any tested performance to stand behind. Almost every failed inspection on a London block of flats falls out of exactly this kind of drift.

02 · The FDIS 7The seven components an FDIS inspection checks

The Fire Door Inspection Scheme (FDIS), run by the Guild of Architectural Ironmongers and the British Woodworking Federation, is the UK's recognised third-party inspection scheme. FDIS Certificated Inspectors (Golden Member status is the senior grade) follow a seven-component checklist that has become the de-facto standard. Below is what each component actually tests, and the most common thing that fails.

BS 8214:2026, the current Code of Practice for timber-based fire door assemblies in England, Scotland and Wales, is the methodology document an FDIS Certificated Inspector will reference in their report. It brings together the BS 476-22 and BS EN 1634-1 test standards, the PAS 80:2003 fire-door naming convention, and the practical on-site interpretation that turns a test result into an inspection judgment.

03 · Gaps & sealsGap tolerances, intumescent strips and cold-smoke seals

If one component of a fire door causes more failures than any other, it is the gap. Everyone understands in principle that a fire door should close tightly against its frame; in practice, paint, humidity, hinge wear and frame movement conspire to make the perimeter gap drift. Inspection gauges are cheap; lack of one is no excuse.

Intumescent strips are the first line once the fire has started. Cold-smoke seals are the first line before it does. Both matter, and crucially, they fail independently. Intumescents can be crushed, painted over, or installed in the wrong groove; cold-smoke seals (brush or fin) fail by wear, by tearing, or simply by being never fitted in the first place. The inspection test: slide a feeler across the seal at every point around the perimeter, and check continuity. A single gap of 50mm in a cold-smoke seal lets a surprising amount of smoke through a corridor door in the first three minutes of a fire.

A fire door fails one component at a time. Gaps drift, seals perish, handles get replaced, closers weaken. The reason quarterly inspections work is that they catch the drift before it stacks up into a single door that will not do its job on the night.

04 · Self-closersSelf-closers and positive latching

Every fire door in a common part of a residential building is a self-closing door. The closer is the least visible component and the one most likely to be ignored, beaten up, or disabled by residents who want their door propped open. It is also the component that determines whether the door will actually perform in a fire, an FD30 door wedged open is an FD0 door.

1. Power size. Self-closers are graded 1–7 by EN 1154. FD30 in a typical residential corridor needs at least a Grade 3 closer; wider or heavier doors and external doors push to Grade 4 or higher. Corridors with mechanical ventilation creating air-pressure need an extra grade.
2. Positive latching. The door must close and engage its latch from any open position without manual help. Test every door in a residential block; it should swing from 90 degrees and latch without a hand on it.
3. Adjustability. A good closer has separately adjustable sweep speed (the main closing motion) and latch speed (the final close). Sweep should be moderate (not slamming); latch speed should be firm enough to overcome the latch spring.
4. Hold-open devices. Where doors genuinely need to be held open (ground-floor refuse-room doors, some care-home bedroom doors), the hold-open must be an electromagnetic device linked to the fire alarm system and must release on activation. Rubber wedges and fire extinguishers used as door stops are a permanent inspection fail.
5. Inspection cadence. Under FS(E)R 2022 Reg 10, common-parts fire door closers in a building over 11m must be checked at least annually; flat entrance doors quarterly. Residents are usually happy to accept a self-closer check as part of a wider door inspection, what they push back on is the discovery that the wedge has to go.

05 · Failure modesThe ten failure modes we find most often

Aggregating roughly 8,000 fire-door inspections HSE has carried out on London buildings over recent years, below are the ten most common findings in rank order. The distribution is consistent across HMO, block, and care-home stock.

1. Non-fire-rated replacement ironmongery. Handle, lock or escutcheon swapped by a resident or a sub-contractor with parts that have no fire rating. Voids certification.
2. Perished or missing intumescent / cold-smoke seals. Ten-year-old doors that have never been maintained. The cold-smoke fin brushes are usually first to fail.
3. Gap drift at the head and closing edge. Outside tolerance by 2–4mm after years of paint and frame movement. Remediable; rarely replaceable.
4. Self-closer set too weak to overcome door friction. Door fails to latch positively. Either a grade issue or adjustment drift.
5. Rubber wedge or other physical prop holding the door open. Common on refuse-store and kitchen doors in HMOs.
6. Retrofit letter plate without certification. Installed for convenience, removes the certified rating in its entirety.
7. Missing or inappropriate hinges. Two hinges instead of three, or non-fire-rated butts installed during a repair.
8. Threshold seal missing or seized. Drop-seal never fitted, or fitted but never maintained; brush seal worn to a stump.
9. Painted-over intumescent strips. Decorator's mistake, repeated every redecoration cycle. The paint prevents the strip expanding fully.
10. Historic vision-panel modifications. Non-certified fire glass; oversized aperture; no bead detail. Almost always voids the rating and requires full leaf replacement.

06 · Worked exampleA 60-flat London block inspection, what the numbers look like

07 · FAQsQuestions building managers and freeholders keep asking

08 · Where to go nextTwo practical follow-ups

If you are a managing agent, freeholder or RTM officer with a block portfolio to get in order, these are the two reads that close the loop.

First, the Building Safety Act s.156 and HRB Duties guide, the 12-minute regulatory brief covering how the Fire Safety Order was amended by s.156, the five new Responsible Person duties, and how HRB status changes the whole compliance stack.

Second, subscribe to The HSE compliance briefing. One email a month with technical fire-safety updates and one actionable thing to do before the next inspection cycle. When FDIS, BS 8214 or the Fire Safety Regulations issue new guidance, you will hear it from Thomas within the week.