Fire door FAQs

Fire doors slow the spread of fire and smoke by containing these hazards within a specific area of a building. This containment helps keep escape routes such as corridors and stairwells clear for longer, giving occupants more time to evacuate safely. Fire doors also reduce damage to property and support the fire service in controlling the incident.

Fire doors work as a barrier that resists the passage of fire and smoke for a set period of time, based on their fire rating. They are built from fire-resistant materials and fitted with components such as intumescent strips, which expand when exposed to heat to seal gaps around the door, and smoke seals to block smoke spread.

Self-closing devices ensure the door is kept shut, which is essential for it to perform effectively during a fire.

Fire doors are made from fire-resistant materials such as timber that has been treated so that it is fire-resistant, metal, or composite cores reinforced with materials like gypsum or steel.

The specific construction depends on the fire rating required, but all components are tested together as a complete doorset to ensure certified fire resistance.

Not all fire doors are solid wood. While some older or traditional fire doors may be made from solid timber, most modern fire doors are constructed with an engineered or composite core, such as particleboard, flaxboard, or mineral-based materials, designed to resist fire for a set period.

Regardless of the core, the door must be tested and certified as a complete doorset to meet fire safety standards.

Not all composite doors are fire rated. A fire-rated composite door is specifically designed and tested to withstand fire for a set duration, such as FD30 (30 minutes) or FD60 (60 minutes).

To be compliant, the entire doorset—including the door leaf, frame, glazing, hardware, and seals—must be tested and certified as a unit.

Standard composite doors without certification should not be assumed to provide fire resistance.

Standard uPVC doors are not fire rated, as the material softens and fails quickly when exposed to heat.

However, there are specialist fire-rated uPVC doorsets that have been reinforced and tested to achieve ratings such as FD30, meaning they can resist fire for 30 minutes.

As with all fire doors, certification of the complete doorset is essential to confirm compliance.

Fire doors are not designed specifically to be soundproof, but because of their solid construction and the use of seals around the edges, they often provide a good level of sound reduction compared to standard doors.

Many fire doors are dual-certified for both fire resistance and acoustic performance, with ratings that specify how much noise they reduce. However, their primary purpose remains fire and smoke containment, not sound insulation.

Most fire doors in the UK are either 44mm thick for an FD30 rating (providing 30 minutes of fire resistance) or 54mm thick for an FD60 rating (providing 60 minutes). Doors with higher ratings, such as FD90 or FD120, are usually even thicker and may incorporate additional layers of fire-resistant materials.

The exact thickness is part of the doorset’s certification, which confirms it has been tested to meet the required fire performance standard.

A fire door must have at least three fire-rated hinges to comply with UK standards such as BS EN 1935 and BS 8214. These hinges are designed to withstand high temperatures and hold the door securely in place during a fire.

Larger or heavier fire doors, or those with higher fire ratings, may require additional hinges as specified in the manufacturer’s specification.

Yes, most fire doors are required to have a self-closing device so they remain shut when not in use, as they can only perform effectively if closed.

UK regulations, including Approved Document B of the Building Regulations, require self-closers on fire doors in commercial buildings, flats, and houses in multiple occupation (HMOs).

In some low-risk domestic situations, such as certain doors within single-family dwellings, self-closers may not always be required, but they are strongly recommended to maintain fire protection.

Intumescent strips are fitted around the sides and top edges of a fire door, not along the bottom.

The bottom gap must meet the maximum clearance specified in the door’s specification (often around 3–4mm).

If extra protection is required at the threshold, a tested fire- and smoke-rated drop seal or threshold seal should be used instead of an intumescent strip.

Fire doors do not need to be lockable, but they must be fitted with hardware that does not prevent safe escape in an emergency.

If locks are used, they must comply with fire safety standards and allow quick, easy opening without a key from the escape side, such as with thumb-turns or panic hardware.

The key requirement is that the locking mechanism must not compromise the door’s fire resistance or restrict evacuation.

If a fire door needs to be rated for smoke then the maximum gap allowed is 3mm. If it does not need to be rated for smoke, the bottom gap can be up to 10mm  in line with BS 8214 and manufacturer specification This clearance ensures the door can close properly while still containing fire and smoke.

A larger gap at the threshold can significantly reduce the door’s effectiveness, and if a bigger clearance is unavoidable, a tested and certified fire- and smoke-rated threshold seal should be installed.

A nominal fire door is a door that appears to be constructed in line with traditional fire door specifications, such as being around 44mm thick and made from solid timber, but it has not been tested or certified as a fire-resisting doorset.

Since the door lacks official testing and certification, its fire performance cannot be guaranteed. For compliance, only fully tested and certified fire doors should be relied upon.

A notional fire door is an existing older door that was originally built to the fire-resisting standards in place at the time of its installation, but it may not meet current testing or certification requirements.

These doors are often found in older buildings and may still offer some fire resistance, but their performance cannot be assured without assessment.

Door handles should be CE/UKCA marked BSEN1906. The complete set of hardware fitted to a fire door — including hinges, latches, locks, and handles — must be suitable for use on fire doors and tested as part of a certified doorset.

Handles made from materials that can withstand high temperatures are recommended, and any hardware used must not compromise the door’s fire resistance.

Always follow the fire door manufacturer’s specification to ensure the correct ironmongery is installed.

Fire doors need to be fitted wherever there is a requirement to protect escape routes, separate high-risk areas, or compartmentalise a building to slow the spread of fire and smoke.

In domestic settings, this includes between an integral garage and the house, in houses of multiple occupation (HMOs), and in some multi-storey homes.

In non-domestic and commercial buildings, fire doors are required in corridors, stairwells, kitchens, plant rooms, and other areas identified by fire risk assessments or building regulations.

Yes, fire doors need to be certified to prove they have been tested and shown to provide the required level of fire resistance.

Certification applies to the complete doorset — the door leaf, frame, glazing, seals, hinges, and hardware — as these components are tested together.

Using certified fire doors ensures compliance with building regulations and gives assurance that the door will perform as intended in a fire.Nominal or notional doors can be acceptable depending on the fire risk assessment.

Fire doors can only be certified by accredited third-party certification bodies, such as BM TRADA or Certifire, after the doorset has been tested to recognised standards like BS 476 or BS EN 1634.

Certification confirms that the complete doorset — including the door leaf, frame, glazing, seals, and hardware — meets the required fire performance.

Installers and inspectors cannot “certify” a fire door themselves, but they can check that a door carries the correct certification marks and labels from the manufacturer or certification body.

No, not anyone can fit a fire door. Fire doors must be installed by a competent person with the necessary skills and knowledge to follow the manufacturer’s instructions and specification requirements.

Poor installation, such as incorrect gaps, unsuitable hardware, or missing seals, can seriously reduce a fire door’s performance.

Many certified fire door installers are registered under third-party schemes like FIRAS or BM TRADA Q-Mark to provide assurance of compliance.

You can only fit a fire door to an existing frame if the frame is proven to be compatible and meets the required fire resistance standard.

The frame must be in good condition, of the correct material and dimensions, and capable of achieving the same rating as the fire door leaf.

In most cases, certified fire doors are supplied as complete doorsets with a matching frame, and using anything else without manufacturer approval can invalidate the certification and compromise safety.

Yes, fire doors can have glass, but only if the glazing is made from tested and certified fire-resistant glass and installed as part of a fire-tested system. The glass must be fitted using approved glazing beads, intumescent seals, and materials specified in the door’s certification.

Standard glass is not suitable, as it will quickly fail in a fire, so only certified fire-rated glazing should be used.

Yes, you can paint a fire door, but only with suitable paints or varnishes that will not affect its fire-resistant properties. The door’s edges, intumescent strips, and seals must not be painted over, as this can stop them working correctly.

Always follow the manufacturer’s guidance, as using inappropriate finishes or excessive layers of paint could compromise the door’s certification.

A fire exit can be used as a normal door if it is designed and intended for regular access, but it must remain easy to open in an emergency without the use of a key.

The exit route must be kept clear at all times, and the door hardware, such as panic bars or push pads, must not be obstructed or altered.

Using a fire exit for day-to-day access should not compromise its primary purpose as a safe means of escape.

No, fire doors should not be wedged open, as they can only prevent the spread of fire and smoke if fully closed.

Wedging a fire door open is a common safety breach that can put lives at risk by allowing fire and smoke to move freely through a building.

If a fire door needs to be held open for accessibility or convenience, it must be fitted with a certified hold-open device or magnetic release that automatically closes the door when the fire alarm is activated.

It is only acceptable to hold a fire door open if it is done using an approved, certified device such as an electromagnetic holder or free-swing door closer that releases the door to close automatically when the fire alarm sounds. These systems maintain the door’s fire safety function while allowing convenience in normal use.

Using wedges, hooks, or other unauthorised methods to hold a fire door open is never acceptable, as it compromises fire protection.

Fire doors should be kept closed at all times unless they are fitted with a certified hold-open device that will release them automatically if the fire alarm is activated. Keeping them closed ensures they can contain fire and smoke, protecting escape routes and limiting damage.

In practice, this means doors to stairwells, corridors, and high-risk rooms such as kitchens and plant rooms should always be closed when not in immediate use.

“Fire door keep shut” signs should be fitted at eye level on both sides of any fire door that must remain shut, in line with the Health and Safety (Safety Signs and Signals) Regulations 1996. This ensures the instruction is clearly visible to anyone approaching the door from either direction.

The signs are a mandatory requirement on non-domestic fire doors and act as a reminder that the door must not be left open or obstructed.

The lifespan of a fire door depends on its quality, usage, and how well it is maintained. With proper care, including regular inspections and timely replacement of worn components like hinges, seals, and closers, a fire door can last many years.

There is no fixed replacement period in law, but if a fire door becomes damaged, altered, or fails to meet its certification requirements, it should be repaired or replaced immediately to remain compliant and effective.

A fire door will hold back a fire for the duration of its certified rating, most commonly 30 minutes (FD30) or 60 minutes (FD60). Higher-rated doors, such as FD90 or FD120, can provide 90 or 120 minutes of resistance.

The actual performance depends on the complete doorset, including the frame, glazing, seals, and hardware, all of which must be tested together to achieve the stated fire resistance.

Yes, fire doors are designed to prevent the spread of both smoke and fire but only if they are properly fitted and closed.

Certified fire doors include intumescent strips that expand in heat to seal gaps against fire and many also have smoke seals to block smoke at cooler temperatures.

To be effective, the door must be installed and maintained as a complete tested doorset with the correct frame, hardware, and seals.

The minimum time for a fire door to close is usually set by the manufacturer and must comply with BS EN 1154 (for controlled door closers) and BS 8214.

In practice, a fire door fitted with a self-closing device should close smoothly and fully onto the latch from any open position, typically within about 5 to 10 seconds. It should not slam shut or remain partially open, as this would compromise its fire performance.

A fire door is not a fire door if it has not been tested and certified as a complete doorset, or if it has been altered or installed incorrectly so that it no longer meets its certified standard.

For example, excessive trimming, missing intumescent strips, uncertified glazing, or oversized gaps can all compromise its performance. In short, without valid certification and correct installation, a door cannot be relied upon to function as a fire door.

In flats, the responsibility for fire doors depends on their location.

The flat entrance door, which opens onto a shared corridor or stairwell, is the responsibility of the landlord, freeholder, or managing agent, as it forms part of the building’s fire protection.

Fire doors located inside the flat are usually the responsibility of the flat owner or tenant.

This division of responsibility is set out in fire safety legislation, including the Fire Safety Act 2021 in England.

Whether you need fire doors in your house depends on its size, layout, and use.

In most single-family homes, building regulations only require a fire door between an integral garage and the house, and sometimes to rooms above two storeys.

In houses of multiple occupation (HMOs) or flats, fire doors are required on escape routes and high-risk rooms such as kitchens.

Even if not legally required, fitting fire doors can significantly improve safety by slowing the spread of fire and smoke.

External doors do not usually need to be fire rated, as their main function is to provide access, security, and weather protection rather than fire resistance.

However, if an external door forms part of a designated escape route or is close to a boundary where fire spread could affect another property, building regulations may require it to be fire rated.

The need for a fire-rated external door should always be confirmed through the building’s fire risk assessment and relevant regulations.

You can identify a fire door by looking for a certification label or plug, usually found on the top or side edge of the door, which shows the manufacturer, fire rating (e.g. FD30, FD60), and certification body.

Fire doors are also usually heavier and thicker than standard doors, fitted with intumescent strips and sometimes smoke seals around the edges, and mounted on at least three fire-rated hinges.

If a door lacks a certification mark, its fire resistance cannot be guaranteed.

Fire doors in non-domestic buildings and communal areas of flats should be checked regularly to ensure they remain in good working order and provide effective fire and smoke protection.

• In non-domestic buildings, fire doors should be checked at least every six months as part of routine maintenance.
• In blocks of flats, communal area fire doors must be checked at least every three months if the building is 11 metres or taller, and regularly in smaller buildings.
• Flat entrance doors must be checked at least once a year in buildings 11 metres or taller, and regularly elsewhere.

In higher-risk premises, or where doors are heavily used, more frequent checks may be required. Routine inspections should confirm that doors close fully and securely, and that gaps, seals, hinges, and self-closing devices are all in good condition and working effectively.