What is the difference between FD30 and FD60 fire doors?
FD30 and FD60 fire doors differ in how long the tested door assembly holds back fire: at least 30 minutes for FD30 and at least 60 for FD60. FD60 doors are usually thicker and heavier, with larger seals and stronger ironmongery. Which one you need depends on the wall or floor the door sits in.
By Sebastian Grabowski, DC Fire & Security, Luton. Updated November 2026.
What the numbers mean
The number is minutes of fire resistance, measured as integrity: the time the door keeps flames and hot gases from passing through to the other side when it is tested in a furnace. Approved Document B describes the rating this way, based on the test to BS 476-22 (or the European equivalent, BS EN 1634-1). An S after the number, as in FD30S, means the doorset is also tested to limit the leakage of cold smoke at normal temperatures, which is why flat entrance doors and stair doors carry it.
Two things catch people out. First, the rating belongs to the whole assembly: the leaf, the frame, the seals, the hinges, the closer and the glazing, fitted the way they were tested. Approved Document B says the test evidence must apply to the complete installed assembly and that small differences in detail can significantly affect the rating. Second, integrity is not insulation. Fire doors often give little protection against heat passing through, which is why the guidance limits how much of a compartment wall can be made up of door openings.
FD30 and FD60 side by side
| FD30 | FD60 | |
|---|---|---|
| Resists fire for | At least 30 minutes, tested | At least 60 minutes, tested |
| Typical use | Flat entrance doors, doors to stairs and corridors, many internal doors | Doors in walls or floors that need more than 30 minutes, which in larger buildings can include plant rooms, risers and stairs |
| The leaf | Usually thinner and lighter | Usually thicker and heavier |
| Seals | Intumescent strip, plus smoke seals on an S door | Usually larger or more strips, and smoke seals where needed |
| Hinges | Fire-rated, usually three | Fire-rated, often more or heavier |
| Frame and glazing | Must be tested for that door | Must be tested for that door |
| Cost | Lower | Higher, priced per job |
Do not read a thickness off the table as a test. Leaf thickness varies between manufacturers, and a thick door is not an FD60 door unless the certificate says so.
Where each rating is used
Approved Document B ties the rating to where the door sits. A door in a compartment wall that separates a flat from a space in common use needs 30 minutes with smoke control, which is FD30S. Doors forming the enclosure of a protected stairway are the same. A door in a wall that separates two buildings needs the same rating as the wall with a minimum of 60 minutes, a door in a compartment floor needs the same as the floor, and in many other compartment wall positions the door needs half the wall's rating with 30 minutes as the minimum. That is how a 120-minute wall ends up with an FD60 door.
So the right rating does not come from a rule of thumb. It comes from the building's fire strategy, or its fire risk assessment, and the position of the door. Some buildings specify FD60 for flat entrance doors or stair doors as a design choice. Ask for the strategy before you order.
Why you cannot upgrade an FD30 door to FD60
Nothing added to an FD30 leaf turns it into an FD60 door. A thicker leaf in an FD30 frame, extra boards on the face, or a heavier closer does not carry the test evidence, and the frame, seals and hinges have to match the FD60 tested detail too. The practical route is a new FD60 doorset, or a new FD60 leaf in a frame that is certified for it. If you are not sure the frame is suitable, a complete doorset is the safer choice. See our fire door installation page for the options.
The same applies in reverse: fitting FD30 doors where FD60 is specified is a non-compliance, whatever the doors look like.
How to tell which door you have
You cannot tell from the face of the door. Look for a label, a plug in the edge of the leaf or the frame, or a certificate that came with the doorset. Painted-over labels and doors with nothing on them are common, and a missing label does not by itself fail a door, but it makes the rating impossible to prove. Government guidance says modern fire doors should show their fire resistance rating. Our guide to how to identify a fire door goes through the places to look, and fire door certification schemes explains what the certificates mean.
An inspection records the rating of every door where it can be identified, and flags the ones that cannot.
What changes in price and lead time
FD60 costs more than FD30: a heavier leaf, a more specified frame, bigger seals and stronger ironmongery. We price FD60 doorsets per job from measurements and photos, and we do not publish a standard figure. Glazed, double and steel doors add their own costs, covered in glazed fire doors and steel against timber fire doors. For the general picture on cost, see fire door supply and fit.
Frequently Asked Questions
Is FD30S the same as FD30?
Do flat entrance doors need to be FD60?
Can I fit an FD30 door where FD60 is needed?
Does FD60 cost more than FD30?
How do I know which fire door I have?
Send us photos or your report
Email your report or photos to info@dcsecurity.co.uk, or use the form. We usually come back with a fixed price the same day. Luton, Bedfordshire, Hertfordshire, Buckinghamshire and London.
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