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This page makes no certification or fire-performance claim about any specific product. Always confirm requirements with your local building control officer.
FD30 and FD60 are the fire door designations that come up most often on UK projects, and the difference is frequently mistaken for a simple question of thickness. Here is what the notation is generally taken to mean.
Short answer
In general industry usage, the number after "FD" refers to a nominal fire integrity period in minutes, assessed for a complete doorset under controlled test conditions. FD30 refers to a nominal thirty minutes and FD60 to a nominal sixty. The rating describes leaf, frame, seals and ironmongery working together as one assembly, not the leaf alone. Which designation applies to your opening depends on the building and the current Building Regulations, so confirm it with your local building control officer before ordering.
What the FD notation means
"FD" is trade shorthand for fire door, and the number after it is generally understood as a nominal integrity period in minutes. That figure comes from assessment of a complete doorset under laboratory conditions, which are controlled and repeatable. A real fire behaves differently, so read the number as a comparative classification rather than a promise.
Drawings sometimes add a letter suffix, commonly relating to smoke control. Usage varies between documents, so ask your specifier to confirm the full designation shown on your drawings rather than inferring it. The notation says nothing about acoustic performance, security or suitability for a given opening.
The difference in intended integrity period
The headline difference is simple: thirty nominal minutes against sixty. What follows from it is less so. An FD60 doorset is not an FD30 with more minutes attached, and the two are not interchangeable in either direction without a decision from whoever holds the fire strategy.
Leaves intended for the longer period are usually heavier and thicker, which changes the demands on the frame, the fixings into the structure, the hinges and any closing device. Substituting upwards is therefore not automatically the safe choice, so raise any proposed change before you order.
Where each rating is typically discussed
Broadly, the shorter period is discussed most often in domestic contexts such as doors serving an escape route, loft conversions, and openings between a house and an integral garage. The longer period tends to come up around compartmentation, larger buildings, and commercial or multi-occupancy settings. Our FD30 fire doors and FD60 fire doors collections are grouped along those lines for browsing convenience only.
Treat that as background. The requirement for any opening depends on the building's use, height and layout, the escape strategy, and the current Building Regulations as they apply to your project, so establish the requirement before you shop. Where the specification permits glazing, glazed fire doors are among the options, and the wider fire doors range shows the general landscape.
Why a fire door performs as a system
This is the most important point here. A fire door is assessed as a doorset: the leaf with its frame or lining, intumescent and smoke seals, hinges, latch or lock, any closing device, any glazing and beads, and the way it is installed into the structural opening.
Performance belongs to that assembly, not to the leaf by itself. Components not shown to work together may not deliver the intended result, however sound each item is individually. Mixing a leaf from one source with frame, seals and ironmongery chosen elsewhere on price is what causes trouble at inspection.
- Follow the manufacturer's installation instructions for the product you bought, not general advice.
- Do not cut, plane, drill or rebate a fire door beyond what those instructions expressly permit.
- Keep the documentation supplied with the product and hand it to whoever inspects the work.
- Raise any proposed substitution with your building control officer before it is fitted.
Seals, hinges, closers and ironmongery
Intumescent seals are designed to expand when heated so the gap around the leaf closes as conditions change. Whether they sit in the leaf or the frame, and what size to use, are matters for your doorset's instructions. Our intumescent strips and pads section exists so you can source what those instructions call for, not so you can choose a seal by eye.
Hinges
Hinges carry a heavier leaf and must stay serviceable in the conditions the door is meant to withstand, so purpose-made fire rated hinges are normally specified. Quantity, size and fixings should come from the manufacturer's documentation rather than from habit. Our guide on how to choose door hinges covers general principles, and the doorset instructions take precedence wherever the two differ.
Closing devices
Where a door must be self-closing, the device is part of the assembly rather than an accessory, so the choice follows the specification. Our door closers range is a starting point once you know what is required.
Installation and maintenance
A correctly specified doorset that is badly installed may not do what the specification intended. Frames need fixing into the structural opening as the instructions describe, with gaps around the leaf inside the stated tolerances. Our internal frames section covers frames generally, but a fire doorset needs one the specification allows.
Those tolerances are typically tighter than on ordinary internal doors, so measure accurately before ordering. Our guide on how to measure for an internal door explains the general method, with the caveat that trimming allowances for fire doors are set by the manufacturer and are usually far more restricted. Once fitted, seals, closers and hardware need checking periodically, and in some buildings those checks are a duty on a responsible person.
Confirming the specification
Nothing here should be used as the basis for a specification decision. Requirements are set by the current Building Regulations and supporting guidance as they apply to your building, and interpreting them for a project is the job of your local building control officer, your architect, or a suitably qualified fire engineer.
Before ordering, we suggest having three things in writing: the designation required for each opening, the frame, seals and ironmongery the doorset requires, and the manufacturer's installation instructions. If any is missing, pause. Our fire door guide gives more background, and you can contact us for help identifying what documentation a manufacturer supplies.
Comparison
| Consideration | FD30 | FD60 |
|---|---|---|
| Nominal integrity period | Thirty minutes | Sixty minutes |
| Typical leaf | Generally the lighter of the two | Generally the heavier of the two |
| Commonly discussed for | Domestic escape routes, loft conversions, integral garages | Compartmentation, larger buildings, multi-occupancy settings |
| Frame and opening | Must suit the doorset as specified | Must suit the doorset, with the greater leaf weight allowed for |
| Ironmongery | Per the manufacturer's instructions | Per the manufacturer's instructions |
| Who decides which applies | Your building control officer, architect or fire engineer, against the current Building Regulations | |
Frequently asked questions
Can I fit an FD60 door where an FD30 was specified?
Do not assume so. The heavier leaf changes the demands on the frame, fixings and hinges, and the substitution may not be supported by the documentation for either product. Ask your building control officer first.
Does the rating apply to the door leaf on its own?
No. The designation relates to a complete doorset including frame, seals, hinges, any closing device and any glazing, installed as the manufacturer describes. A leaf in an unsuitable frame is a different assembly.
Can I trim a fire door to fit my opening?
Only within the limits the manufacturer's instructions expressly allow, and those are usually much tighter than for a standard internal door. Check the permitted allowance for that specific product before ordering.
Do I need a door closer on every fire door?
Not necessarily. Self-closing is required in some situations and not others, depending on the building and the fire strategy. Confirm with your building control officer which openings need a closing device.
Who checks that the installation is acceptable?
On notifiable work that is normally a matter for building control, sometimes with input from a fire risk assessor. Keep the manufacturer's documentation so it can be produced at inspection.