Why FD120 Fire Doors Are the Heavyweight Champions of Fire Protection
When most people think of fire doors, they picture the ones they see in offices, schools, or apartment corridors — usually rated FD30 or FD60, meaning they’ll hold back fire for 30 or 60 minutes.
But in certain environments, that’s simply not enough. Some buildings need more than an hour of protection to allow people to escape safely and keep fire from destroying critical infrastructure. That’s where the FD120 fire door comes in — a specialist product that offers a full two hours of certified fire resistance.
The Meaning Behind FD120
The “FD” stands for Fire Door, and the number tells you how many minutes it’s been tested to resist the passage of fire and smoke. In the case of FD120, that’s 120 minutes — and it’s not just marketing speak.
Every FD120 door must be tested to strict British or European standards, such as BS 476-22 or BS EN 1634-1, in conditions that replicate the intense heat, flames, and pressure of a real fire. The result is a product you can trust to perform when it matters most.
Where FD120 Doors Earn Their Keep
You’re unlikely to find an FD120 door in a small office or a block of flats — but in industrial sites, chemical plants, large commercial kitchens, high-rise service cores, and plant rooms housing essential equipment, they’re often an essential part of the fire safety strategy.
In these high-risk areas, the fire load (the amount of combustible material present) is greater, evacuation may take longer, and the consequences of a fire spreading can be far more severe. That extra hour of protection beyond an FD60 door could mean the difference between a controlled incident and a catastrophic loss.
Why They’re a Specialist Product
FD120 doors aren’t just thicker versions of lower-rated doors. They’re engineered from the inside out with:
Dense fire-resistant cores designed to withstand extreme heat for prolonged periods
Specialist intumescent seals that expand in heat to block flames and smoke
Certified ironmongery — hinges, closers, locks, and glass vision panels all rated for 120 minutes
Precision manufacturing to ensure the door, frame, and hardware all work as a tested assembly
Every component is part of a system. Swap one element for a non-rated alternative and you’ve compromised the door’s performance.
Kent Flush Doors and FD120 Manufacturing
At Kent Flush Doors, we understand that FD120 fire doors aren’t just another product line — they’re a safety-critical solution for specialist environments.
Our manufacturing process combines:
Full certification under BM Trada to meet UK fire safety standards
Tailored design to suit the exact application, whether that’s a plant room, data centre, or industrial facility
Bespoke finishes that combine safety with the aesthetic requirements of modern architecture
From single bespoke door sets to multiple-unit supply for large projects, we work with architects, contractors, and facilities managers to ensure every FD120 door leaves our workshop ready to protect people and property.
The Bottom Line
In a fire, time is everything. FD120 fire doors give you an extra hour of resistance compared to FD60 — an extra hour for people to evacuate, for firefighters to gain control, and for vital equipment to be saved.
If your building’s fire strategy demands the highest level of passive fire protection, Kent Flush Doors can deliver a CERTIFIED FD120 solution you need — without compromise.