An FD120 fire doorset provides a minimum of 120 minutes' fire resistance, demonstrated by testing to BS 476-22 or BS EN 1634-1 and, on the European route, classified under BS EN 13501-2. Two hours is the highest rating in the common UK FD series and is reserved for the most demanding compartmentation: major compartment walls, high-hazard storage and process areas, and positions identified by fire engineers where failure of the opening would have serious consequences.
At 120 minutes, performance is unforgiving of substitution. The leaf construction, frame, intumescent protection and every item of ironmongery must match the tested and certified design, and installation must follow the certificated method. Every FD120 doorset we supply will be a complete factory-assembled unit under a third-party certification scheme — frequently steel construction at this rating, with certified timber-based designs available for particular applications.
FD120 requirements are always project-specific. We will work from the fire strategy and the manufacturer's certification data to confirm achievable sizes, configurations and hardware before quotation, and each doorset will be delivered with its certificate references, installation instructions aligned to BS 8214, and the specification records needed for Regulation 38 handover and golden thread documentation.
Specification
| Fire resistance | 120 minutes minimum (FD120), tested to BS 476-22 or BS EN 1634-1 |
| Leaf thickness | Determined by the certified design; heavier construction than lower ratings |
| Core | Specialist high-performance core or steel construction as covered by the doorset's certification scope |
| Seals | Enhanced intumescent seal configuration per the certificated 120-minute design |
| Testing route | BS 476-22 or BS EN 1634-1, classified to BS EN 13501-2 on the European route |
| Smoke variant | Cold smoke seal variants available where specified, subject to the certified design |
| Glazing options | Highly restricted at 120 minutes; where offered, factory-fitted fire-rated glazing strictly within the certified field of application |
| Acoustic options | Subject to the certified design; confirmed against the doorset specification at enquiry |
| Ironmongery | CE/UKCA-marked heavy-duty hardware within the certification scope: hinges to BS EN 1935, closers to BS EN 1154, compatible locks and latches |
| Third-party certification scheme | Published at launch |
| Lead times | Published at launch |
Typical applications
- Major compartment walls where 120-minute separation is specified
- High-hazard storage, process and plant areas
- Transformer rooms, generator rooms and fuel storage positions
- Basement and infrastructure compartmentation in large or complex buildings
- Positions identified in fire-engineered designs requiring maximum-duration containment
Options
- Steel or certified timber-based construction to suit the specification
- Cold smoke control variants where the certified design permits
- Pair (double-leaf) configurations within the certified scope
- Heavy-duty closers to BS EN 1154 and hold-open devices to BS EN 1155 where the fire strategy permits
- Security and access-control integration within the certification scope
- BS 5499 'Fire door keep shut' signage
Not sure which rating you need?
See fire door ratings explained and FD30 vs FD60: which rating do you need? — or run the compliance checker to find your legal duties.
We will supply FD120 doorsets on their own or installed to BS 8214 with full handover evidence.
Fire door supply →Frequently asked questions
What is an FD120 fire door?
An FD120 doorset provides at least 120 minutes of fire resistance when tested to BS 476-22 or BS EN 1634-1. It is the highest rating in the common UK FD series and is specified for major compartment lines and high-hazard areas, almost always as the result of a fire-engineered design or explicit compartmentation strategy rather than general guidance.
Are FD120 doors always steel?
Not always, but steel construction is common at this rating because of the performance demanded over two hours. Certified timber-based FD120 designs exist for particular applications. What matters is that the whole doorset — leaf, frame, seals and ironmongery — matches a tested, third-party-certified design; we will confirm the appropriate construction for each project from manufacturer certification data.
Do FD90 and FD120 doorsets cost more than FD30 and FD60?
Generally yes — heavier construction, specialist cores and more restricted supply chains mean higher ratings typically cost more, and pricing is project-specific rather than list-based. We will quote FD90 and FD120 doorsets individually against the specification, and our pricing approach will be published at launch.