Painting Fire Doors in London: What Is and Is Not Permitted
A clear guide to painting fire doors in London commercial and residential buildings: what the regulations permit, intumescent paint requirements, third-party certification, and the risks of getting it wrong.
Painting Fire Doors in London Buildings
Fire doors are a critical element of passive fire protection in London's residential and commercial buildings. They are legally required to maintain their fire resistance rating throughout their service life, which means that any painting or refurbishment must be carried out in a way that does not compromise their integrity. Getting this wrong is not just a regulatory matter -- it can have fatal consequences in the event of a fire.
This guide explains what the regulations require, which painting operations are and are not permitted on fire doors, and what intumescent products are needed when painting around fire door assemblies.
What Makes a Fire Door Different
A fire door is not simply a heavier-than-normal door. It is a complete assembly -- door leaf, frame, hardware, intumescent seals, and smoke seals -- that has been tested as a system to resist the passage of fire and smoke for a defined period. The most common ratings in UK buildings are FD30 (thirty minutes) and FD60 (sixty minutes), though higher ratings exist in hospitals, high-rise residential buildings, and industrial settings.
Every component of the assembly contributes to the rating. Replacing one component with a non-tested equivalent, or applying a coating that the test did not include, can in principle invalidate the door's fire resistance. This is why painting a fire door is a more significant undertaking than painting any other door in a building.
What the Regulations Say
The regulatory framework governing fire doors in England and Wales includes the Building Regulations (specifically Approved Document B on fire safety), the Regulatory Reform (Fire Safety) Order 2005, and, for higher-risk residential buildings, the Building Safety Act 2022.
Under the Regulatory Reform (Fire Safety) Order, the responsible person for a building -- the employer, the managing agent, or the building owner in some cases -- must ensure that fire doors are maintained in good working order and to the standard at which they were installed. Any maintenance or refurbishment must not reduce the door's fire resistance.
For residential buildings containing two or more domestic premises (the vast majority of London apartment blocks and converted houses), the Building Safety Act 2022 has strengthened the inspection and maintenance requirements for fire doors significantly. Regular inspections are now mandated, and any remedial work including painting must be documented.
What Is Permitted: Repainting Fire Door Leaves
In many cases, fire doors can be repainted. The critical conditions are:
The existing door must not be a surface-coated door whose coating forms part of the fire test. Most solid timber core FD30 doors rely on the core material for their fire resistance, and a new coat of paint over an existing sound painted surface is generally acceptable, provided the paint system does not significantly increase the total build thickness and does not include materials that would impair the door's fire resistance.
The paint must be compatible with the door's tested configuration. Some manufacturers specify that only certain paint types should be used on their doors. Where the door has a current third-party certificate (such as a BM TRADA Q-Mark or BWF Certifire certificate), the scope of that certificate may specify permitted maintenance operations.
Total paint build must not be excessive. Multiple layers of paint built up over years can cause a fire door to stick in its frame, preventing it from closing fully -- which is one of the most common fire door failures found in London residential buildings. Where paint build-up is excessive, it must be stripped back before repainting.
Intumescent Strips and Seals: Do Not Paint Over Them
The intumescent strips set into the rebate of a fire door frame -- and sometimes into the door leaf edge itself -- are designed to expand when exposed to heat, sealing the gap between door and frame and preventing the passage of fire. Painting over these strips reduces their effectiveness and can invalidate the door's certification.
Intumescent strips must be identified before any repainting work begins and must be masked or left unpainted throughout the operation. If the existing strips are damaged, missing, or have been painted over in previous operations, they must be replaced by a competent person using a product specified for that door and frame configuration.
Smoke seals (the brush or compression seals that run around the door rebate to prevent cold smoke passage) must similarly not be painted over.
When Intumescent Paint Is Required
Intumescent paint is a specialist coating that contains chemicals which expand significantly when exposed to heat, forming an insulating char layer that delays the spread of fire. It is not a standard painting product and is not routinely applied to fire doors in most buildings.
The contexts in which intumescent paint is specified for fire doors include:
- Upgrading a door that does not meet current FD30 or FD60 requirements without replacement, where an intumescent paint system has been specifically tested and certified for that purpose.
- Certain structural steel elements adjacent to fire door assemblies where additional fire protection is required.
- Some heritage and listed building contexts where replacing the door is not possible and a certified intumescent coating system provides an approved alternative.
The application of intumescent paint systems must be carried out strictly in accordance with the product manufacturer's instructions and the relevant test specification. The paint is typically applied in a defined number of coats to a defined dry film thickness, verified with a gauge. Incorrect application provides no protection. Third-party certification of the completed work should be obtained where the installation forms part of a required fire protection strategy.
Practical Advice for London Building Managers
For most London apartment buildings and commercial premises, the practical position is:
- Have fire doors inspected annually by a competent person, as required by the Regulatory Reform (Fire Safety) Order.
- Where doors need repainting, use a decorator who understands fire door requirements and will document the work carried out.
- Do not strip and repaint fire door edges, rebates, or hardware without taking advice from a fire door specialist first.
- Never paint over intumescent strips or smoke seals.
- Keep a maintenance log for each fire door in the building, recording inspections, any work carried out, and the products used.
Belgravia Painters works with managing agents and building owners across London on fire door maintenance and repainting programmes. We carry full public liability insurance and can provide documentation of all work carried out for compliance records. Contact us to discuss your building's fire door requirements.