Calling all landlords and employers – are fire doors fitted in your businesses and homes?
A fire door can be the difference between life and death, restricting smoke and flames from spreading through a building to allow enough time for the evacuation of employees, tenants, and members of the public. Landlords and employers are legally responsible for ensuring the fire safety of their buildings and properties, and this includes proper installation of fire doors that adhere to fire door regulations.
Treating solid wood doors with fire-resistant coatings and fittings can help comply with your local authority’s building regulations for fire doors – we will look at these products and components as well as why and where fire doors are needed in the home and business.
Fire is serious business and you should seek advice from our technical advisors before buying or fitting any fire-resistant upgrade products. Contact us on the number below:

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What is a fire door, and what are they for?
Do I need fire doors in my home or business?

What is a fire door, and what are they for?
Doors with a fire-resistance rating are known as Fire Doors and are used as part of a passive fire-protection system, reducing spread of smoke and fire between compartmentalised rooms, spaces, buildings and structures.
Fire doors are very important for fire safety as they are designed to reduce the likelihood of a fire developing. A correctly-fitted and functioning fire door should restrict the flow of oxygen to a fire, supressing and preventing it from enlarging. Fire doors are also designed to block the spread of fire for a specified amount of time, usually between 30 minutes and up to an hour, preventing a fire from moving through the door and into adjacent rooms or corridors, which could cause more damage to property as well as the structural integrity of a building.
Do I need fire doors in my home or business?
Businesses
Building Regulations require that escape routes are protected by fire doors. This allows enough time for people to evacuate when the alarm is raised, protecting them from fire as they do so, and offering some protection to firefighters as they enter the building. Any door that opens onto an escape route, especially a stairwell, should be fire-resisting.
As fire doors are designed to prevent fire from leaving or entering a space, all businesses should look to compartmentalise their buildings using fire doors, especially where expensive machinery is used, such as:
- Hospitals and clinics
- Workshops and garages
- Factories and warehouses
- Offices and data centres
Schools
Employers, head teachers, governors and vice-chancellors are legally responsible for the fire safety of their school buildings to ensure that staff and pupils can evacuate in an emergency. Science classrooms and laboratories should especially be flagged on fire risk assessments for needing fire-resistant doors, as well as communal areas like gyms, assembly halls, and corridors. Fire doors restrict airflow to a fire and prevent the spread of smoke and flames, and must be fitted to protect escape routes in institutions such as:
- Nursery schools
- Primary schools
- Secondary schools
- After-school clubs
- Universities
- Academies
- Free schools
- Music schools
- Special schools
- Sunday schools
- Adult education centres
- Pupil referral units
Flats and Houses
Fire doors should be fitted to all habitable rooms, such as bedrooms, that lead to a stairwell in 3 or more storey homes. This helps to keep fires contained and allows passage down the stairs for evacuation. For loft conversions the door must be fire-resistant; fire can travel through lofts of adjoining properties with ease and work their way through a building from the top down. Integral garages that lead into homes should also have fire doors between them.
In flats and homes with multiple, unrelated tenants (Homes of Multiple Occupancy, or HMO’s), the door for each living space should be fire resistant, with “Fire Door: Keep Shut” signs on them as well as doors leading to communal kitchens and living rooms. Fire door regulations require doors to match the fire-resistance rating of partitions; 30-minute partitions will need a 30-minute fire resistant door (FD30), and the same for 60-minute ratings (FD60).
The legislation for the use of fire doors can be detailed and complicated for landlords and employers to digest. We would recommend calling your local council’s housing department for clarification on fire door regulations and for any updates to the law before committing to a project.

Fire Door Upgrades
We would recommend installing custom-built fire doors for your property, ensuring that they are properly fit and function correctly. However, some properties may have strict planning regulations and/or are listed preventing removal or substantial change to be made to interior doors, or they may be significantly large or small, such as loft hatches and access doors. For these, our fire door upgrade kits can help satisfy authorities involved in projects aimed at increasing the fire resistance of wooden doors, but steps should be taken before committing to a project involving our products, including reading the differences between types of door. A written specification should be obtained from our Technical Department for your project prior to use to ensure the proposed system will be suitable. Contact us by phone on 0113 2455450 or email [email protected], products should not be purchased/used without this. We also recommend all product data sheets, system information and any relevant test data is read, understood and forwarded to your authority for approval/comment. Information is available to download from the ‘DATASHEETS’ tab on each product page but we also suggest you speak to our Technical Department to ensure you have the most current versions and ALL relevant documentation relating to your project as information is being updated regularly due to new testing, product developments, legislation changes, etc. Remember, intumescent paints and varnishes are just one element of protection and DO NOT create a ‘fire door’. Doors should only be considered for upgrade when the historic integrity of the door must be maintained, evaluation of ironmongery and gaps around the door should be undertaken and then all works should be carried out by a specialist to meet the requirements of your authority. |
Paint Systems
Fire-resistant doors don’t necessarily have to be bland and bulky and devoid of character; Thermoguard Timbercoat Door Upgrade System, for example, is available in over 4,000 colours so you don’t have to compromise on appearance, whilst still improving its fire resistance. Great for the home, such as bedroom and loft doors, and important for shops that build their shopping environments for a better consumer experience, especially in an age where more consumers skip the high street and buy online.
Previous paints often don’t need to be stripped off – just prepare the door and then apply the fire-resistant coatings. Application can be carried out by brush or spray.
The system contains the correct amount of intumescent coating and top coat to finish 2 doors on both sides per pack, and as with most products you can also request a Certificate of Supply, signed by the applicator which can be shown to your local authority if requested for verification.
While Thermoguard recommend the installation of custom built fire doors there can be reasons not to do so. Doors that Thermoguard Timbercoat is capable of upgrading are ones that can afford to lose 2mm to charring.
Note: Well seasoned or old, sturdy doors with panels 8mm thick can be upgraded if additional “sacrificial” ply panels 6mm thick are fitted in the panel recesses and held in place by the door’s beading If your doors are in a category which could be upgraded submit your assessment to your Authority, along with Thermoguards explanatory Technical Note (available to download HERE) for approval prior to purchase. |
Varnish Systems
Thermoguard Fire Varnish Door Upgrade System is an intumescent varnish system to upgrade solid doors to 20 or 30min Fire Resistance. Available as a convenient pack containing the required basecoat, topcoat and mastic to protect 3 doors in a clear or woodstain coloured Matt or Satin finish. Suitable for certain, bare hardwood solid doors, improving the fire resistance with minimal fuss. Iideal for properties with strict building regulations that prevent the removal or substantial changes to the original internal doors in listed and graded buildings.
Please refer Thermoguard’s explanatory Technical Note (available to download HERE) to the appropriate Authority for approval before proceeding. Due to the hugely varying nature of doors and their construction, it is impractical and misleading to carry out NAMAS / UKAS Fire Test Laboratory fire door testing. Each door must be assessed for potential suitability.
The great majority of doors, including all hollow doors, are unsuitable for upgrading to 30 or even 20 minutes Fire Resistance.
There are, however, certain well constructed, solid and substantial doors capable of being upgraded with the Thermoguard Fire Varnish system as this is by far the most effective clear fire treatment or coating available.
Generally suitable doors are hardwood or solid with hardwood veneer.
Intumescent paint (white or coloured) is capable of significantly greater Fire Resistance. If you have softwood doors we suggest you refer to Thermoguard Timbercoat Door Upgrade System.

Door Seals
For a fire door to function as required, it needs to be fitted correctly. Fixing a fire-resistant seal into the bottom of the door helps to close gaps, sealing in smoke and flames for a specified time period, and helps to starve a fire of oxygen to prevent it from growing. Rebated and surface-mounted seals sit inside door frames to seal up the space between the door edging and frame and can usually be painted over once installed.
Always be sure that the seal properly plugs the gap under a fire door. Separate threshold ramps can be used for extra protection, raising the floor to meet the door, without obstructing the use of wheelchairs in schools, hospitals, care homes and the workplace.
Glazing Protection
Intumescent wooden beads and glazing strips protect fire doors with screens, usually seen in schools and hospitals where staff may need to observe those inside of a room, without interrupting. The bead sits either side of the glazing and is coated with intumescent to expand during fire. This prevents flames from entering the fire door through gaps near the screen.
Letterbox Systems
Your fire door may be fitted correctly, treated with the appropriate coatings, and seals up all the gaps, but if you have a letterbox fitted then this too must also be fire-resistant to meet fire door requirements.
Letterbox units resist attacks from fire for up to an hour, with intumescent linings that expand to fill any gaps between the unit and the door. There are extra options and accessories to further upgrade their fire resistance, with smoke seals and lockable rear flaps that prevent flammable objects being dropped through the door.
Letterbox Fire Bags and Boxes
If using a locking letter plate isn’t viable with your fire door, consider using a fire box instead. These metal boxes sit on the back of your door and collect mail as it is put through the letterbox. Any objects pushed through the door that are on fire, intending to commit vandalism or arson, are contained by the fireproof box. The box is designed with intumescent lining that expand to seal up any gaps and starves the fire of oxygen, intending to extinguish flames.
For doors with limited space behind them, flexible fire bags can be used instead with the same functionality, and work with vertical letterboxes too. Both varieties are ideal for properties that have an exposed letterbox during out-of-hours, such as doctors surgeries and libraries, or for homes (rented or otherwise) in areas where police advise that attacks could be likely.
Ventilation Grilles
Some internal fire doors may house chemicals such as cleaning solutions and fluids for council swimming pools and gyms, and drugs and medicines in laboratories and hospitals. These cupboards should be ventilated as, when opening the door, the build up of chemical smells could overwhelm a person and cause asphyxiation.
Using ventilation grilles fitted with intumescent material, fire doors can remain resistant to fire whilst still ventilating an area. Fire-rated vents have an assortment of facings such as louvre, as well as automatic grilles that close up during fire to prevent the spread of smoke or flames through a fire door, or even ventilation ducting.
Door Closers and Hinges
A fire door isn’t much good if it’s left propped open. Human negligence is one of the biggest factors to consider when filling out your fire risk assessment for your home, school or business, and having a fire door close automatically will help negate that. Options include door-closing hinges and timed magnetic door holders, you must also consider why a fire door is being left open.
Always contact your relevant authority / Building Control Officers to check which doors they require protecting and seeking their approval for your proposed products and course of action prior to purchase and use of these systems.
As standards vary widely throughout the UK from property to property and region to region, it is important to check your doors have been installed correctly and meet the minimum requirements of the product you wish to use. A fire door paint or varnish may be suitable for your project but not all doors are suitable and many need to be replaced.
Fire is serious business and you should seek advice from our technical advisors before buying or fitting any fire stopping products. Contact us on the number below:
