Fire, Security & Electrical Blog

10 Answers to Common Questions about Fire Doors

Fire Doors and Fire Exit Signs

Last Updated on 12 March 2021.

Don’t be fooled, there’s a lot more to that hulk of wood than you think.

Fire doors are an essential component of your building’s passive fire protection.

The WFP experts have put together an easy guide here on everything you need to know about fire doors to keep your premises safe and legal.

1. What are fire doors and how do they work?

Fire doors are an engineered safety device, which, when closed, act as a barrier to compartmentalise fire and smoke, delaying its spread to other areas of the building. On the flip side, when they’re open, they provide a means of escape and give the emergency services a protected route to access a building.

Imagine it like dominoes. Not the pizza, the game.

The spread of fire is like a domino effect; there are no obstacles so each piece continues to fall, the fire continues to spread. If you were to place down an obstacle, you’d soon see the chain reaction grind to a halt. The obstacle is containing the fire, so it’s now safe to move forward.

They’re an essential part of a building’s make-up, constructed with fire resistant materials specifically for the purpose of containing fire and smoke.

2. How long can fire doors withhold fire and smoke?

This depends on the fire door rating, which indicates how long the door can resist fire door. The British Standard’s most common ratings (as specified in BS 476-22) are FD 30 and FD 60, which resist fire for 30 minutes and 60 minutes consecutively. However, you can also have ratings which allow up to 120 minutes of fire resistance, but the minimum you should ever find is 30 minutes. The design of the building and the nature of its day-to-day operation will determine the category of fire door which should be installed.

However, it’s important to remember that fire doors can fail, they’re not infallible. A fire door can only do its job if it is kept closed, undamaged and well maintained!

3. What are the components which make up a fire door?

There are various components which make up a fire door; you will typically be able to identify the following:

Door leaf – this is the door itself which must be manufactured and certified with a suitable fire rating to the building it will be contained in.

Door frame – this must be compatible with its counterpart, the door leaf, and fitted correctly to ensure the gaps are appropriate and meet the size needed to fulfil its function.

Smoke/Fire seals – these should fill all of the gaps around the door leaf when closed.

Intumescent strips – unlike smoke seals which retain their current form at all times around the frames of fire doors to block fire and smoke, intumescent strips expand when exposed to extreme heat, further sealing the gap around the door frame.

Hinges – these must have the correct fixings in the right locations, as well have appropriate hinge pads, to ensure the door opens and closes efficiently.

Door closer – this is another facilitator to ensure the door closes automatically; you’ll usually see a metal box attached to an arm behind the fire door at the top (which often goes unnoticed!), although not all fire doors have a door closing mechanism.

Fire Door Self-Closing Device

Latch/lock (to ensure that the fire door remains closed) – this is also fitted within intumescent protection for fire/smoke resistance.

Threshold seals – this closes the gap underneath the door leaf when closed.

Signage (clearly indicating that it is a fire door so they should be kept shut) – you will usually see a blue circular sign on a fire door indicating that it is a fire door and must be kept shut.

Some fire doors also have glazed panels and must be suitably fire resistant, as well as fitted with intumescent glazing seals. Air grilles are also used where extra ventilation is required, which are then designed to close if the fire alarm is activated. You may also see on some fire doors additional ironmongery such as push bars and push pads to provide easy escape in an emergency.

4. Why are fire doors important?

In reality, people are more often affected by smoke before the fire itself. Fire doors are a lifesaver in this scenario because they can withstand smoke and fire. The smoke seals, for example, around the door edge and frame seal the gaps to prevent the smoke getting through, preventing smoke inhalation. Similarly, intumescent strips expand to several times their original size when exposed to heat to seal the gaps around the door to contain the fire and smoke.

They’re an extremely important part of your building’s fire safety strategy.

5. Are fire doors and the maintenance of fire doors a legal requirement?

Yes! The Regulatory Reform (Fire Safety) Order 2005 (RRO), which applies to all non-domestic and communal areas, stipulates that the ‘Responsible Person’ (typically a building owner or manager) must undertake steps to remove and reduce fire risks. This includes duties such as carrying out a Fire Risk Assessment and conducting recommendations from the assessment to enable a safe and legal environment, as well as offering adequate fire safety training for staff members.

New buildings or older buildings which have undergone an alteration or extension are also subject to Building Regulations (also known as Approved Documents) which is a rule book for legal compliance which builders must follow, whilst existing buildings are subject to the RRO as mentioned above.

Then there are various codes outlined by British Standards for the design, installation and maintenance of fire doors:

The BS 8214:2008 provides guidelines on the specifications of fire door assembly and recommendations for inspections.

The BS 9999:2009 offers a code of practice for building design and management, which takes into account emergency exits for disabled and vulnerable persons. This can be referred to for the design of new buildings, as well as extensions and alterations.

The BS 5839-1:2017 relates to the design, installation, commissioning and maintenance of fire alarm systems. This applies to fire doors in relation to Door Hold Open devices, for instance where the fire alarm has an operational cause-and-effect to immediately shut all fire doors in the event the alarm is activated.

Failure to take adequate action in installing and maintaining fire doors within your building places lives at risk and can result in prosecution.

6. How often must fire doors be serviced?

British Standards (namely BS 8214 and BS 9999) recommend having a fire door maintenance service/inspection every six months, however the best course of action is to have a risk-assessed recommendation which will be tailored specifically to your building requirements. For example, your premises may have a higher footfall than others and may require more frequent inspections. Your Fire Risk Assessor will tell you how often your fire doors should be serviced during your Fire Risk Assessment.

Following the Grenfell Fire in 2017, remediation projects and investigations in both passive and active fire protection are taking place across the UK. The Fire Industry Association noted following one building surveyor’s findings that there was a distinct lack of maintenance records, missing or incorrect fire escape signage, and even cases where fire doors had been locked or had the intumescent seals painted over, which completely negates their use.

So, without regular inspections, your fire doors could be completely ineffective without your knowledge. Simply having fire doors in place doesn’t mean that they’re in good working order – like everything, it needs maintaining.

7. Who should service fire doors?

Like all of your passive and active fire safety equipment within your building, it should be maintained by a competent specialist who holds the appropriate insurances and UKAS accreditations. This means their practices are audited by third-party certification schemes and follow British Standards. UKAS accredited bodies for fire doors include BM TRADA Q-Mark Certification, Certifire (Warringtonfire), IFC Certification Ltd, BlueSky Certification and BRE Global.

Always remember to ask for accreditations to ensure the provider you choose is trustworthy and competent to service your building’s fire doors, and retain the service reports for your records as evidence of your due diligence to keep your building safe and legal.

8. What do I do in between maintenance service visits?

Something that is largely overlooked is checking fire doors in-between services. We recommend that weekly checks are carried out for obstructions to fire doors (and also if any are being left open!) and visual inspection for any damage to hinges, ensuring they close properly without sticking on the frame. Any damage should be reported immediately to your fire door maintenance provider for repair.

Useful observations and questions to ask yourself when carrying out your weekly fire door checks include:

  • Does the fire door shut fully and tightly on its own using its self-closing device?
  • Is the self-closing device damaged in any way? (E.g. is it leaking oil and is the arm secure and functional?)
  • Is the gap between the door lead and the door frame less than 4mm?
  • Is the door leaf and door frame in good condition and undamaged?
  • Do the hinges appear to be loose or damaged?
  • Are all handles secure and functioning without any issues?
  • Are intumescent and smoke seals in good condition (i.e. not missing, damaged or painted over)?
  • Is the door marked with the appropriate signage to indicate it is a fire door?
  • Are any fire doors being obstructed or left open?

Fire Door Keep Shut Blue Sign

9. Where do fire doors need to be?

Fire doors are needed in all public, commercial and multiple occupancy buildings. (So, you won’t, for instance, need fire doors in your typical family house but you will need them in a block of flats.)

For domestic dwellings more than two storeys high, a fire door is required on every level to separate the stairwell from every habitable room. They’re also needed in loft conversions and between a house and an integral garage.

For mixed-use buildings, you’ll need a fire door to separate non-domestic (business) areas from domestic (residential) parts of the building.

For non-domestic buildings, it’s a little more complicated as each building is different. Guidance states the building is divided into separate sections for horizontal and vertical escape routes. This is usually factored into the make-up of the building’s design before it’s even built.

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10 thoughts on “10 Answers to Common Questions about Fire Doors”
    1. Hi Joyce,

      Thanks for your comment! Your front door will have your flat number but your nearest fire escape door and/or the the fire door outside of your front door does not need to have your flat number on it (at least, it’s not stipulated anywhere that you require it). Depending on the design of your building, e.g. if one fire escape door leads onto many apartments, you might sometimes find a sign which says something like ‘flats 23-27’ on one side. The point of a fire door is to provide a guard between you and a fire, and for fire escape doors to also provide a safe means of exit, so in the event of a real fire the most important thing is to safely evacuate (when safe to do so, and if your building is operating under a simultaneous evacuation protocol due to cladding/fireproofing issues) or stay put for the fire brigade to fight the fire (if your building is not operating under a simultaneous evacuation). Can I ask anyway, what’s prompted you to ask this? Are there concerns you currently have with your multi-storey tower block with regards to fire safety we can help with? We have an article which might be of interest to you here on what tower blocks are doing to mitigate fire safety risks: If you’ve got any further questions then please do give us a shout!

  1. twsfiredoorsurveys

    All the points are described so well. Would love to read these type of blogs. Yes, fire door are something which we should maintain time by time and you need experts for that and we are here to help.

  2. Colin Phillips

    I live in a block of flats and maisonettes and my front door opens onto an exterior covered walkway. Am I legally obliged to have a ‘fire-door’ fas my front door?

    1. Hi Colin,

      Thank you for your question! I believe you called our office and spoke to my colleague, Elle. You will need to ascertain what your fire risk assessment says, which your property managers should have a copy of. This will dictate whether fire doors are needed. If you’d like to refer us to them to help them with this then we’d be more than happy to help further on this!

  3. You state the following in inspecting a fire door. “Are intumescent and smoke seals in good condition (i.e. not missing, damaged or painted over)?”
    This is not correct, intumescent seals/strips can be painted over, which is basically decoration of a fire door. It would not be advised, but you can paint over an intumescent seal, up to five times. Mick

    1. Hi Michael,

      Thank you for your comment. I’ve referred to our fire door specialist on this and they have confirmed that the statement of “Are intumescent and smoke seals in good condition (i.e. not missing, damaged or painted over)?” refers to the combined intumescent and smoke seal. These seals are formed of either an intumescent and brush, or intumescent and blade. These combined seals cannot be painted over.

      However painting of intumescent fire seals (only) should be avoided where possible. Our experience and training by our 3rd party accreditation advises that intumescent seals should not be painted in any circumstance unless product used has test evidence to support such claims. The number of coats that can be applied is a grey area. If seals have been sanded or a heat gun has been applied to remove the previous layer of paint, this would void the seal entirely.

      I hope this helps?

      Kind regards,

      Verity (Head of Communications at WFP)

  4. Can someone advise on regulations regarding certification of fire door leafs. Iv recently purchased 5 fd30 doors fr leader doors, had them installed and now it’s been noted by the building inspector that the doors have no markings on them. Leader doors have sent me a document which lists numerous doors being tested but not one relates to the doors I have purchased. I have been unsuccessfully trying to claim they have sold me something unfit but I can not find specific documentation that states fire doors must come with relevant proof of fire performance. It’s all guidance. This is a real nightmare. Can anyone advise?


    1. Hi Gareth,

      Our fire door specialist says you should return to ‘Leader Doors’ and request the certification relating to the door leafs they have supplied. The door leaf supplier, i.e. the organisation who places the certificated product on the market is responsible for the control of product conformity and its traceability.

      Kind regards,

      Head of Comms

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