When a fire breaks out, every second counts. The ability of a door to contain flames and smoke long enough for people to evacuate – and for firefighters to respond – can be the difference between minor damage and catastrophe. That’s the role of the fire door, one of the most vital yet misunderstood components of modern building safety.
In the UK, fire door ratings and standards are tightly regulated to ensure that these barriers perform exactly as expected under extreme conditions. From FD30 doors in homes to FD120 installations in industrial sites, understanding these ratings – and how they’re certified – is essential for architects, contractors, facilities managers, and homeowners alike.
This guide breaks down what fire door ratings really mean, how they’re tested, and where regulations require them, giving you a clear roadmap to full compliance and safer building design.
What Are Fire Door Ratings?
Definition and Purpose
A fire door rating indicates how long a door can resist the passage of fire and smoke during a test that simulates real fire conditions. The rating is expressed in minutes – for example:
- FD30 means the door has been proven to resist fire for at least 30 minutes
- FD60 means 60 minutes
- Higher ratings, such as FD90 or FD120, provide 90 and 120 minutes of protection respectively
The goal of any fire door is twofold:
- To delay the spread of fire and smoke, allowing safe evacuation
- To contain damage, preserving structural integrity and minimizing property loss
It’s not just about protecting the door itself – it’s about giving people time.
Common UK Fire Door Ratings and What They Mean
| Rating | Resistance Time | Typical Use |
| FD30 | 30 minutes | Residential homes, internal flat entrance doors |
| FD60 | 60 minutes | Commercial buildings, corridors, stairwells |
| FD90 / FD120 | 90–120 minutes | High-risk areas: industrial sites, plant rooms, server rooms |
In many installations, you’ll also see FD30S or FD60S, where the “S” indicates smoke control – the door is fitted with smoke seals to limit toxic fume migration before the fire itself reaches that section.
Integrity vs. Insulation
- Integrity measures how long flames are prevented from penetrating the door.
- Insulation measures how long the door prevents heat transfer that could ignite materials on the safe side.
Both factors are crucial, especially in escape routes or compartmented areas.
UK Fire Door Testing Standards
To ensure consistency and reliability, fire doors in the UK are tested to recognized British and European standards. These standards dictate how a door is exposed to fire, what constitutes failure, and how performance is recorded.
BS 476 Part 22: The Traditional British Standard
BS 476 Part 22 is the long-established British testing method for determining the fire resistance of building elements, including doors.
- Assesses both loadbearing and non-loadbearing doorsets
- Determines performance under direct exposure to a controlled fire
- Remains widely used for UK-only products not requiring CE or UKCA marking
Doors tested to BS 476 Part 22 are rated according to how long they withstand structural failure and integrity loss. Many FD30 and FD60 doors on the UK market today are certified under this standard.
EN 1634-1: The European Fire Resistance Test
EN 1634-1 is the harmonized European standard that aligns testing across the EU and UK (now under UKCA marking post-Brexit).
- Specifies the same performance criteria as BS 476, but uses European test equipment and classification
- Required for CE- or UKCA-marked fire doors sold across borders
- Allows for uniform product comparison and international recognition
In practice, both standards are considered valid, but EN 1634-1 is increasingly preferred for new certifications and export-ready installations.
Who Certifies Fire Doors in the UK?
Fire doors aren’t simply “rated” by manufacturers – they must be tested and certified by accredited third-party organizations. This ensures traceability and accountability throughout a door’s life cycle.
The most recognized schemes include:
- Certifire (by Warringtonfire)
- BM TRADA Q-Mark
- IFC Certification
- BlueSky Certification
Certified fire doors come with:
- A permanent label or plug (usually at the top of the door)
- Documentation verifying test results
- Manufacturer and certification body details
Always request this certification when purchasing fire doors. Without it, you can’t prove compliance – and an uncertified door may invalidate your building’s fire risk assessment.
When Are Fire-Rated Doors Required?
The need for a fire door depends on building type, layout, and occupancy. UK Building Regulations (Approved Document B) outline minimum requirements for various situations.
Residential Settings
- Flats and Apartments: The main entrance door to each flat must be FD30S, providing both 30-minute fire resistance and smoke control.
- Houses with Three or More Storeys: Any door between the living area and the stairwell must be FD30.
- Garage-to-House Doors: If your garage connects directly to your home, the internal door must be FD30, with an automatic closer.
Commercial and Public Buildings
- FD60 or higher doors are typically required for escape routes, stair cores, corridors, and plant rooms.
- Fire doors should be installed along compartment walls, dividing the building into zones that restrict fire spread.
- The precise rating depends on the building’s size, occupancy type, and fire strategy.
For a deeper breakdown of where and when fire doors are required in different property types, refer to this UK Fire Door Regulations Guide from Latham’s.
What Does a Compliant Fire Door Include?
Every component of a fire door assembly must work together to achieve its rated performance. A compliant installation should include:
- Certified fire-rated core (solid timber, composite, or steel)
- Matching frame tested as part of the doorset
- Intumescent seals that expand when exposed to heat
- Smoke seals (for “S” rated doors)
- Fire-rated hinges and hardware (minimum 3 hinges per leaf)
- Self-closing mechanism, where required by regulations
- Certification label or plug, clearly visible
- Gap tolerance of 3–4 mm around the perimeter
Each component must be compatible – mixing untested parts invalidates the fire rating.
Fire Door Maintenance and Inspections
A certified door is only compliant if it’s maintained properly. Over time, seals perish, hinges loosen, and closers fail – all of which compromise performance.
Routine checks should include:
- Verifying that seals and closers are intact and functional
- Ensuring door gaps remain within tolerance
- Checking that hinges and latches are secure
- Confirming that the certification label remains visible
It’s recommended to have doors inspected annually by an FDIS-accredited inspector or a competent fire safety professional. In high-traffic or multi-occupancy buildings, inspections may be required more frequently.
Conclusion
Fire doors are not passive architectural elements – they’re engineered safety systems designed to contain disaster. Understanding fire door ratings and standards such as FD30, FD60, BS 476 Part 22, and EN 1634-1 isn’t just about compliance – it’s about responsibility.
Whether you’re specifying materials for a new build, retrofitting an older property, or simply verifying that your home’s internal doors meet current UK regulations, one rule stands above all:
Certification saves lives.
Always choose tested, labelled, and verified fire doors from reputable suppliers. A door that holds for 30 minutes can mean 30 minutes more for firefighters to arrive, 30 minutes more for evacuation, and 30 minutes more between safety and tragedy.