Fire Door Ratings Explained: FD30, FD30S, FD60, FD90 and FD120

What do fire door ratings like FD30 and FD60 mean?

A fire door rating describes how long a fire doorset resisted fire in a standard furnace test. In the traditional UK notation the rating is written as FD — for fire door — followed by the number of minutes achieved: the BWF Fire Door Alliance lists the scale as FD 30, FD 60, FD 90 and FD 120, with an FD 20 rating also appearing in regulatory guidance for a few lower-risk positions. The basis is the British test standard BS 476-22: Approved Document B defines the FD rating in Appendix C as 'fire resistance in terms of integrity, for a period of minutes, when tested to BS 476-22, e.g. FD 30'.

Integrity means the doorset resists the passage of fire — flames and hot gases — from one side to the other for the stated period. That is all the number promises. It says nothing about how hot the unexposed face of the door becomes, which is a separate property called insulation and is measured only under the European classification system covered below.

Just as important: the rating belongs to the complete tested doorset, not to the leaf alone. Leaf, frame, intumescent seals, hinges, closer, glazing and even the gaps between them are tested as one assembly, and Appendix C of Approved Document B requires test evidence to be 'applicable to the complete installed assembly', warning that 'small differences in detail may significantly affect the rating'. A certified FD30 leaf hung in the wrong frame, without its tested seals or hardware, has no demonstrated rating at all.

FD30 and FD60 account for the overwhelming majority of doors you will meet in practice — our guide to FD30 vs FD60 fire doors compares the two in detail.

What does the S in FD30S mean?

The S suffix marks a doorset that also restricts cold smoke — smoke at ambient temperature, the kind that spreads through a building early in a fire, well before the door itself faces flame. Approved Document B puts it simply: 'a suffix (S) is added for doorsets where restricted smoke leakage at ambient temperatures is needed'. A plain FD30 door has proven itself against fire only; an FD30S doorset has also demonstrated smoke control. The BWF Fire Door Alliance uses the same convention across the scale — FD 30 S through FD 120 S.

The pass mark is defined in the notes to Table C1 of Approved Document B. Unless the building uses pressurisation complying with BS EN 12101-6, a smoke-rated doorset must satisfy one of the following:

• Have a leakage rate not exceeding 3m³/m/hour — measured from the head and jambs only — when tested at 25Pa under BS 476-31.1; or
• Meet the additional Sa classification when tested to BS EN 1634-3.

In practice, smoke control is delivered by flexible smoke seals — brush or fin types, usually combined with the intumescent strip in a single seal — working with a self-closer that holds the door snug in its frame. Our guide to intumescent strips and smoke seals explains how the two seal types do different jobs at different stages of a fire.

Sa and S200 under the European standards

The European smoke classes are determined by testing to BS EN 1634-3 and classified under BS EN 13501-2. Sa denotes restricted smoke leakage at ambient temperature — the direct counterpart of the British S suffix, and the class Approved Document B itself cites. S200 is the more demanding class, described in BS EN 16034 guidance as leakage at 'medium temperature': testing to BS EN 1634-3 measures smoke leakage at ambient and elevated (200°C) temperatures. On a full European designation the smoke class is appended to the fire class — for example E 30 Sa, or EI₂ 60 S200 on a doorset classified for both insulation and hot smoke.

How do FD ratings map to E, EI and EW under EN 13501-2?

Under the European system, a doorset is tested to BS EN 1634-1 and the result is classified under BS EN 13501-2 using performance letters combined with a time in minutes:

• E — integrity. The doorset resists the passage of flames and hot gases for the stated period: E30, E60 and so on. This is the closest counterpart to the FD rating.
• EI — integrity and insulation. The doorset also limits the temperature rise on its unexposed face, holding back conducted heat as well as flames. For doorsets the insulation criterion is subdivided into EI₁ and EI₂ classes.
• EW — integrity and radiation. The doorset restricts radiated heat passing through it while maintaining integrity.
• Sa / S200 — smoke. Appended for smoke control, as described above — for example E 30 Sa.

The mapping that matters most: FD30 corresponds roughly to E30 — it is not equivalent to EI30. Both FD30 and E30 are 30-minute integrity ratings; neither requires any insulation performance. Approved Document B is explicit that doorset performance 'is in terms of integrity (E) for a period of minutes', and the European column of its Table C1 asks for E-class doorsets — E 30 Sa for a flat entrance door — not EI. Treating FD30 as interchangeable with EI30 is one of the most common specification errors of the transition period: EI adds an insulation requirement that standard fire doorsets are not designed to deliver. Approved Document B itself notes that 'fire doorsets often do not provide any significant insulation', which is why it limits door openings to a maximum of 25% of the length of a compartment wall unless the doorsets provide insulation too.

Which fire door rating is required where?

For building work in England, Approved Document B sets minimum doorset performance by position in Table C1 — Volume 1 covers dwellings, and Volume 2 contains the equivalent provisions for other buildings. The organising principle is that a fire door should generally match the fire resistance of the wall it sits in: a door 'in a compartment wall separating buildings', for instance, must match the wall 'but a minimum of 60 minutes'. The positions most people need are these:

In practice, many specifiers simply fit FD30 doorsets where Table C1 asks for FD20 or E 20 — a widely available product that exceeds the minimum. Note that the in-dwellinghouse rows are what typically drive fire door requirements in loft conversions, and the garage row is covered in depth in our garage fire door guide.

A rating alone is not the whole requirement. Appendix C also requires all fire doorsets — expressly including flat entrance doors and doors between a dwellinghouse and an integral garage — to be fitted with a self-closing device, with three exceptions: fire doorsets to cupboards, fire doorsets to service ducts normally locked shut, and fire doorsets within flats and dwellinghouses. Our guide to fire door self-closers covers the device types and the rules for holding doors open.

Approved Document B is statutory guidance for building work under the Building Regulations — it does not retrospectively require doors in existing buildings to be upgraded. In occupied buildings the operative duties come from the Regulatory Reform (Fire Safety) Order 2005, which requires fire doors to be maintained in efficient working order, and — in English residential buildings over 11 metres — Regulation 10 of the Fire Safety (England) Regulations 2022, under which communal fire doors must be checked at least every three months and flat entrance doors, on a best-endeavours basis, at least every twelve months. See our guides to Regulation 10 fire door checks and flat entrance fire doors.

How do you check a fire door's rating from its label or plug?

Third-party-certified fire doors carry permanent identification, and reading it is the quickest reliable way to establish a door's rating. Work through these in order:

1. Look along the top edge for a label. When a fire door is manufactured or modified by a BWF Fire Door Alliance member, a label with a unique number is placed on the top edge of the door, displaying the member's name and phone number and, where applicable, the certification number, a unique serial number and the door's fire rating. Open the door and look down at the top edge of the leaf.
2. Look for a colour-coded plug. Timber doors certified under BM TRADA's Q-Mark scheme carry colour-coded fire door plugs, typically set into the top edge or the hanging edge. The colour signals the scope of certification — BM TRADA cautions that 'not all plugs are equal': depending on the colour, the door may be certified only up to the point where it still requires intumescent seals or a certified frame to complete the doorset.
3. Trace the certification data. The label or plug's serial number lets the manufacturer or certification scheme trace the doorset to its certificate and data sheet, which state the rating together with the tested seal configuration, permitted hardware, glazing and gap tolerances.
4. Check the building's handover information. For buildings completed or altered under the Building Regulations, fire safety information handed over under Regulation 38 should record where fire doors are and what was specified.

Leaf thickness is a useful first clue — timber FD30 doorsets are typically 44mm thick and FD60 doorsets typically 54mm — but a clue is all it is. Thickness proves nothing about the core, the seals or the testing, and labels should never be removed or obscured; painting over door edges can hide them, one of several reasons to take care when decorating a fire door.

No label, no plug, no paperwork? Then the rating is unproven, however solid the door feels. A competent inspector can assess an unmarked door against the features expected of a fire doorset, but documentary evidence remains the benchmark — see how to identify a fire door and our overview of fire door certification schemes for what the various marks mean.

What happens to BS 476 and FD ratings from 2029?

Approved Document B is retiring the national classifications in stages. The 2025 amendment booklet, in force from 2 March 2025, removed BS 476 classifications for reaction to fire and roofs. The 2029 amendment booklet comes into force on 2 September 2029 and removes the national classification system (BS 476) for fire resistance from Approved Document B — fire doors included. From that date the European Standard, which the government describes as 'more current and robust than the National Classes', becomes 'the sole route of specification' for fire resistance. A transitional provision allows the outgoing edition to continue to apply where a building notice, initial notice or building control approval application with full plans has been given to the relevant authority before 2 September 2029 and the building work has started and is sufficiently progressed either before that day or within six months beginning on it.

The standards body is moving in step. BSI's summary of the changing status of the BS 476 series records that BS 476-22 is superseded by BS EN 1634-1:2014+A1:2018, and that the fire-resistance parts of the series — including parts 20 to 24 and 31.1 — form the second tranche being removed from statutory guidance on 2 September 2029, with the forewords of affected standards updated to state that they will be withdrawn on that date.

What this means in practice:

• Existing doors are not retrospectively invalidated. The 2029 change affects the specification of new building work; doors already installed continue to be governed by the Fire Safety Order's maintenance duty and the building's fire risk assessment.
• New specifications shift to European classes. For building work in England from 2 September 2029, doorset performance should be specified and evidenced as E with Sa for smoke control — or EI or EW where the fire strategy genuinely calls for insulation or radiation control.
• Buying now, think ahead. For projects that may complete near or after the deadline, prefer doorsets that already hold BS EN 1634-1 test evidence and a BS EN 13501-2 classification. Dual-tested products avoid the cliff edge entirely.