Fire Door FAQs, Frequently Asked Questions 

What is a fire door, and how can I identify one? 

A fire door is a specially constructed door designed to resist the spread of fire and smoke for a specific period of time, helping protect escape routes and give occupants time to evacuate. You can usually identify one by a certification plug or label on the top or side edge of the door, an intumescent strip and smoke seal set into the frame or door edge, and a self-closing device. If none of these are visible, it’s likely not a genuine fire door our fire door survey service can confirm either way.

What is the purpose of a fire door? 

Fire doors are designed to slow the spread of fire and smoke between compartments of a building, protecting escape routes and giving occupants more time to evacuate safely in an emergency.

What is an FD30 fire door? What’s a “notional” or “nominal” fire door? 

An FD30 fire door is rated to resist fire for approximately 30 minutes. A “notional” or “nominal” fire door refers to an older solid-core door that hasn’t been formally tested or certified but is assumed to offer some fire resistance based on its construction; these should not be relied upon as genuine fire doors without proper testing or certification.

What are fire doors made of? Are composite, uPVC, steel, aluminium or pocket doors fire rated? 

Fire doors are most commonly solid timber core construction, but composite, steel and some aluminium doors can also achieve fire ratings if properly tested and certified; the rating comes from the whole door assembly being tested, not the material alone. Standard uPVC doors are generally not fire-rated for internal fire door use. Pocket doors and bifold doors can be fire rated, but only when the specific tested and certified system is used not as a standard retrofit.

How do fire doors work, and how long will they hold back fire and smoke? 

Fire doors work through a combination of a fire-resistant core, intumescent strips that expand when heated to seal gaps, and smoke seals that limit smoke penetration. An FD30 door is tested to hold back fire for around 30 minutes and an FD60 door for around 60 minutes, provided the full door set frame, seals, hinges and closer is intact and correctly fitted.

How long is an NHS fire door tested to contain fire? 

NHS estates fire doors typically follow the same FD30 (30-minute) or FD60 (60-minute) fire resistance testing standards used across other UK buildings, though healthcare settings often specify additional requirements around smoke control and door width for bed/trolley access.

Are fire doors a legal requirement, and where are they needed? 

Yes under the Regulatory Reform (Fire Safety) Order 2005 and the Fire Safety (England) Regulations 2022, fire doors are legally required in the common parts of multi-occupied residential buildings, HMOs, and most commercial and public buildings, particularly along escape routes, between compartments, and protecting high-risk rooms (kitchens, plant rooms, storage areas). The exact number and location of required fire doors depends on the building’s fire risk assessment our fire door survey will confirm exactly what your property needs.

Do I need fire doors in my house, or inside my flat? 

For a standard single-family house, fire doors are generally not a legal requirement unless the property is over three storeys, contains a loft conversion habitable room, or is an HMO. In flats and communal residential buildings, fire doors are required for flat entrance doors and internal fire doors protecting escape routes. Landlords letting HMOs and multi-occupied properties do have a legal duty to install compliant fire doors see our fire door installation page for detail.

Do you need fire doors for a loft conversion?

Yes, in most cases. A loft conversion that creates an additional storey typically requires fire doors on the ground and first floor to protect the escape route, as part of Building Regulations compliance.

Do holiday lets require fire doors to the bedrooms?

Yes. Holiday lets are generally treated similarly to HMOs or commercial accommodation under fire safety guidance, and bedroom fire doors are commonly required as part of a compliant escape strategy this should be confirmed via a fire risk assessment specific to the property.

Who is responsible for fire doors in flats?

The “Responsible Person” typically the freeholder, managing agent, landlord or building owner is legally responsible for ensuring fire doors in communal areas are compliant and maintained. Individual leaseholders are generally responsible for their own flat entrance door.

Who can certify or inspect fire doors?

Fire doors should be inspected and certified by a competent person with genuine training and experience in fire door assessment ideally holding recognised accreditation such as FIRAS, BM TRADA Q-Mark, or equivalent. Liviosiv is NICEIC, NAPIT and IFSM accredited for this work see our fire door survey and fire door certificate pages.

How do I become a certified fire door inspector?

Becoming a certified fire door inspector typically involves completing a recognised training course (such as those accredited by FIRAS or a similar body), gaining practical assessment experience, and passing a competency exam. This is a specialist qualification rather than something added onto general building trades.

Do bathrooms need fire doors?

Not usually, unless the bathroom sits directly on an escape route or within an HMO where guidance requires it. Most domestic bathroom doors don’t need to be fire rated.

Do internal doors need to be fire rated?

Not all of them only those protecting escape routes, high-risk rooms (like kitchens in HMOs), or forming part of a building’s compartmentation strategy, as identified in the fire risk assessment.

Do external doors need to be fire rated?

Generally no, unless they form part of a designated fire exit or escape route, or are located where fire spread risk from an external source is a specific concern.

Do door handles need to be fire rated?

Yes, hardware fitted to a certified fire door (handles, locks, hinges) should be tested and compatible with that specific door’s fire rating, or it can invalidate the door’s certification.

Do fire doors need intumescent strips? 

Yes, virtually all certified fire doors require intumescent strips around the door edge (and sometimes the threshold) these expand when heated to seal gaps and stop fire and smoke passing through. Strips are usually fitted into the door or frame edge rather than the very bottom, though threshold seals are used on some door sets for smoke protection.

Do fire doors need to be self-closing? 

Yes, in almost all cases. A fire door that doesn’t close and latch on its own can’t reliably contain fire and smoke in an emergency, which is why self-closing devices are a standard requirement and one of the most common defects found during a fire door survey.

How many hinges does a fire door need? 

Most fire doors require a minimum of three fire-rated hinges, though heavier or taller doors may need four for correct load distribution and closing performance.

What is the maximum gap allowed around/under a fire door? 

The typical tolerance is around 2–4mm around the top and sides of the door, with slightly different requirements for the threshold gap depending on the door’s certification. Excessive gaps are one of the most common reasons fire doors fail inspection. See our fire door remedial works service if your doors need correcting.

Can fire doors have glass or windows in them?

Yes, but only fire-rated glazing systems, tested as part of a certified fire door assembly, standard glass is not suitable and will compromise the door’s fire performance.

Are Perko (or similar) door closers suitable for fire doors?

Only if the specific closer model has been tested and certified for use on fire doors not all commercially available door closers are fire-rated, so it’s important to check the manufacturer’s certification before fitting.

Why are electromagnetic release devices attached to fire doors? Do magnetic fire door holders need to be released manually?

Electromagnetic hold-open devices allow a fire door to be legally held open during normal use while automatically releasing and closing the door when the fire alarm activates. They release automatically via the fire alarm system; manual release should also be possible, but they shouldn’t rely on someone remembering to close the door manually in an emergency.

Does a fire exit door need a push bar?

Yes, in most commercial and communal settings panic hardware (push bars or push pads) is required on fire exit doors to allow quick, easy escape without needing a key or specific technique to operate the lock.

Can fire doors be locked or bolted?

Fire doors on designated escape routes generally should not be locked in a way that prevents free exit during an emergency any locking mechanism must allow immediate escape without a key from the inside. Push plates aren’t a legal requirement everywhere but are common on doors without vision panels to reduce handprint damage.

Should fire doors be wedged open, or kept closed at all times? 

No fire doors should never be wedged open, as this defeats their entire purpose of containing fire and smoke. They must remain closed at all times unless fitted with an approved, fire-alarm-linked automatic hold-open device. A closed fire door is what stops smoke and flames spreading between compartments.

Can you use a fire exit as a normal, everyday door?

Generally, fire exits should be reserved for emergency escape and shouldn’t be used as a routine everyday entrance/exit, as this can lead to the door being propped open or the closer/latch mechanism wearing out faster than intended.

Where should “fire door keep shut” signs be fitted? 

“Fire door keep shut” signage should be displayed on both sides of the door, at eye level, wherever the door is required to remain closed to maintain compartmentation.

Are fire doors “active” or “passive” fire protection?

Fire doors are considered passive fire protection they work automatically by their construction and design (resisting fire spread) rather than requiring activation like a sprinkler system or fire alarm, which are active protection measures.

How to fit a fire door can anyone install one?

Fire doors should only be fitted by a competent, experienced installer, as incorrect installation is one of the most common reasons a certified fire door fails to perform correctly even a properly certified door can fail if the gaps, seals or hardware are wrong. Most single-door installations take a few hours; see our fire door installation page for our full process.

How do I fit intumescent strips on a fire door?

Intumescent strips should be fitted into a routed groove around the door or frame edge, following the manufacturer’s exact specification for size and position. Incorrect fitting can invalidate the door’s certification, so this is best left to a qualified installer.

How to adjust a fire door closer ?

Most fire door closers have adjustable screws (usually on the closer body) controlling closing speed and latching force; these should be adjusted so the door closes fully and latches every time without slamming. If you are not confident doing this yourself, our fire door maintenance team can adjust it correctly.

How to stop fire doors slamming?

A slamming fire door is usually a sign the closer needs adjusting (closing speed set too fast) rather than something to fix by removing or disabling the closer, which would make the door non-compliant. Have the closer serviced or adjusted rather than removed.

Can fire doors be cut to size?

Only within very limited tolerances specified by the manufacturer cutting a fire door beyond its approved tolerance (for example, to fit a smaller opening) can invalidate its fire rating entirely.

Can you install a door stop on a fire door?

Yes, provided the door stop does not interfere with the door’s ability to close and latch fully anything that could hold the door open (rather than just cushion it) would compromise compliance.

How often should fire doors be inspected or checked?

Recommended guidance is quarterly for communal fire doors in residential buildings, at least annually for flat entrance doors, and roughly every six months for commercial fire doors high-traffic or high-risk doors may need more frequent checks. See our fire door survey page for full detail based on your building type.

How to check/inspect a fire door?

A proper check covers the door leaf and frame condition, gaps (2–4mm tolerance), intumescent strips and smoke seals, hinges, self-closing device, and certification labelling. For anything beyond a basic visual check, a professional fire door survey is recommended.

How long do fire doors last? 

With proper installation and regular maintenance, a fire door can last many years often 15–20+ — but its fire performance depends on all components (seals, closer, hardware) staying intact and correctly maintained throughout, not just the door leaf’s physical condition.

Can fire doors be painted?

Yes, in most cases fire doors can be painted, but the paint should not cover or seal over the intumescent strips, seals, or the certification label/plug doing so can obscure important safety features and, in some cases, affect performance if incompatible products are used.

How much does a fire door cost?

Fire door costs vary depending on the rating (FD30 vs FD60), material, size and glazing see our fire door installation page for a full quote based on your specific requirements.

How much does it cost to fit or install a fire door?

Installation cost depends on whether it’s a leaf-only fit into an existing frame or a full door-set replacement, plus any remedial frame work needed we will confirm a clear price after an initial assessment.

How much does a fire door inspection cost?

Our fire door inspection and certification pricing is £85 per door for up to 6 doors, and £79 per door for up to 12 doors see our fire door certificate page for full detail.

How thick are fire doors?

Standard FD30 fire doors are typically around 44–54mm thick, while FD60 doors are often thicker (around 54mm or more), depending on the manufacturer and construction.

How much do fire doors weigh?

A standard single fire door typically weighs between 30–45kg depending on size, material and construction noticeably heavier than a standard internal door, which is one reason correct hinge specification matters so much.

How are fire doors tested and rated? 

Fire doors are tested as a complete assembly (door, frame, seals, hardware) in accredited fire test chambers, exposed to controlled fire conditions until failure, with the resulting time (e.g. 30 or 60 minutes) forming the FD rating. This is why swapping individual components for uncertified parts can invalidate the tested rating.