Fire Doors Explained: FD30 vs FD60 & Where You Need Them

A fire door is not simply a heavier version of an ordinary door. It is a tested assembly, door leaf, frame, intumescent strips, smoke seals, hinges, and closer, certified to maintain a fire barrier for a defined period. Substituting one component, fitting the wrong hinges, or leaving out the door closer can invalidate the rating entirely.

In UK domestic buildings, fire doors are required in a narrower set of circumstances than many people assume. They are needed in flats, in houses with a floor more than 4.5 m above ground (in practice usually three or more storeys), between integral garages and dwellings, and in HMOs. They are not required in every room of a standard two-storey house.

FD30 vs FD60: What the Ratings Mean

The number in the rating refers to the number of minutes the door must resist fire when tested to BS 476-22 or BS EN 1634-1.¹

FD30 (30-minute integrity): The door must hold back flames and hot gases for at least 30 minutes under test conditions. In homes it is required between a house and an integral garage and at a flat’s entrance door; the doors enclosing a protected stair inside a house need only 20 minutes (E 20, FD 20).²

FD60 (60-minute integrity): The door must perform for 60 minutes. It is used in some commercial premises and, in taller blocks of flats, for the doors into a firefighting shaft, which Approved Document B sets at E 60 Sa; it is rarely needed in a house.²

The suffix S indicates that the door also includes smoke seals. An FD30S door stops both flame and cold smoke. Building Regulations Approved Document B asks for smoke seals on the door between a house and an integral garage and on a flat’s entrance door, but not on the 20-minute doors enclosing a stair inside a house.²

The Components That Make a Fire Door Work

A fire door is only as good as its weakest component. The full assembly must be certified together.

Door leaf: The core itself, usually solid timber, engineered timber, or steel, must be tested and carry a manufacturer’s label (typically a colour-coded plug in the top edge). Never remove or paint over this plug; it is the evidence of conformance.

Intumescent strips: These are fitted into the rebate of the door or frame (or both). When exposed to heat, the strip swells rapidly, sealing the gap between door and frame and preventing flames from passing through. Strips must be the correct size for the gap and the tested assembly, do not fit a generic strip without checking it is compatible with the door’s test certificate.

Smoke seals: A brush or fin seal fitted to the door or frame to reduce cold smoke passage at normal temperatures. Required for all FD30S and FD60S assemblies.

Hinges: Typically three hinges minimum, and they must be steel (or other non-combustible material) of the appropriate grade. Brass-plated hinges that have not been tested as part of the assembly are not acceptable.

Door closer: Approved Document B asks for a self-closing device on fire doors including a flat’s entrance door and the door between a house and an integral garage, but not on fire doors within a flat or a house.² Propping a fire door open with a wedge or removing the closer defeats the assembly, and in a block of flats the building’s responsible person must tell residents to keep fire doors shut and not to tamper with self-closing devices.³

Frame and lining: The frame must also be fire-rated or the door’s performance cannot be achieved. Fitting a fire door into a standard softwood lining on a half-inch planted stop will not provide fire resistance regardless of the door leaf’s rating.

Where Fire Doors Are Required in UK Homes

Integral Garage to Dwelling

Any door between an attached or integral garage and the living accommodation must be FD30S under Approved Document B (Table C1), fitted with a self-closing device.² This applies to new-builds and conversions. If you’re converting an integral garage into a habitable room, the fire separation requirements change, the door that previously protected the dwelling is removed, and fire separation must be achieved by other means (upgraded ceiling, walls, etc.).

Houses with a Floor More Than 4.5 m Above Ground

In England, a house with a floor more than 4.5 m above ground level, which in practice usually means three or more storeys, including a loft conversion that adds one, needs a protected stairway.² That is a stair enclosed in fire-resisting construction (minimum REI 30) at all storeys, and the doors onto it need at least 20 minutes of fire resistance (E 20, FD 20); FD30 doors are often fitted in practice.² This commonly catches homeowners undertaking loft conversions: a simple Velux loft room can require new fire doors on all first-floor rooms once it takes the top floor above 4.5 m.

Flats and Converted Dwellings

The entrance door of every flat must be FD30S with a self-closer.² All doors opening onto the common parts from a flat must be fire-rated. Within the flat itself, where a protected entrance hall is needed, the doors onto it need at least E 20 and need not be self-closing.²

HMOs (Houses in Multiple Occupation)

Houses in multiple occupation are regulated under the Regulatory Reform (Fire Safety) Order 2005 and local HMO licensing schemes. Fire doors are usually required on habitable rooms opening onto escape routes. Your council’s private sector housing team can confirm exactly what is required for your property, HMO requirements vary by occupancy number and property type.

What Fire Doors Are NOT Required For

In a standard two-storey single-family house:

• Internal room-to-room doors do not need to be fire-rated
• Bathroom and toilet doors do not need to be fire-rated
• Cupboard doors (other than meter cupboards in flats) do not need to be fire-rated

You can choose to fit fire doors anywhere for peace of mind, and many homeowners do, particularly on kitchen doors: cooking appliances were the largest specified cause of accidental dwelling fires in England in the year to March 2026, at 42%.⁴ But it is not a legal requirement in these locations for an owner-occupied two-storey house.

Fire Door Costs in 2026

Choosing and Buying a Fire Door

Buy from a supplier who can provide the test certificate or declaration of performance for the door. The label (colour plug) in the top edge of the door leaf should be legible and untouched. Check that the intumescent strip and hinges are included in the tested assembly, some manufacturers supply strips separately and specify which product to use.

Avoid second-hand fire doors unless you can verify the rating, see the label in the top edge, and confirm the door has not been modified (holes cut, rebates altered, edges planed excessively). A fire door that has been trimmed more than the manufacturer allows has an unknown performance.

Fitting: Always Use a Competent Person

Fire door fitting is not the same as ordinary door hanging. The gap between door and frame must be within the tested tolerances: government guidance gives the industry standard as never more than 4 mm, except at the bottom of the door, where it should be as small as practicable.³ The intumescent strip must be continuous and correctly positioned. Where a self-closer is fitted, it must be set to close the door fully from any position without being propped or held.

Building Control approval is required for fire door installation in new-build and conversion work. In existing dwellings, the work does not need to be notified to Building Control in all cases, but the installation must still comply with the Building Regulations if those Regulations apply to the works being carried out. An incompetent installation is not only legally non-compliant, in the event of a fire, it can cost lives.