Every fire door carries a rating that says how long it holds back fire. FD30 is 30 minutes. FD60 is 60 minutes. This post explains what that figure measures, what has to be right for the rating to count, and how to find out what your doors are.
What FD30 and FD60 mean
FD stands for fire door. The number is the minutes of fire integrity the door achieved in a fire test: the time it stopped flames and hot gases passing through to the other side.
| Rating | Fire integrity |
|---|---|
| FD30 | 30 minutes |
| FD60 | 60 minutes |
The rating belongs to the whole doorset as it was tested. That means the door leaf, the frame, the seals, the hinges and the closer together. A rated leaf hung in an unrated frame does not carry the rating.
Which rating a door needs
The rating is set by where the door sits, not by preference. It depends on the wall or enclosure the door is in, its position on the escape route, and the building's fire strategy. Approved Document B and the building's fire risk assessment decide it. Walls and enclosures with a higher fire resistance call for a higher-rated door.
The practical rule is simple. A door must match the rating required for its position. FD30 where FD60 is required gives half the protection time.
What the S in FD30S and FD60S means
The S stands for smoke seal. A door marked FD30S has cold smoke seals fitted as well as the intumescent seals that swell in heat. Many doors on escape routes need to limit smoke as well as fire, so the S version is specified.
What the rating depends on
A doorset only holds its rating when every part is in place and in working order:
- Door leaf and frame fitted as the tested, matched set
- Intumescent seals fitted continuously and not painted over
- Cold smoke seals fitted where the S rating applies
- A self-closer that shuts the door fully and latches it every time
- Hinges, handles, locks and glazing that are rated for the doorset
- Gaps around the leaf within the limits in the door's certification
How to tell what rating a door has
Look at the top or edge of the door leaf. Many certified doors carry a label, tag or plug that identifies the rating and the certification scheme. The manufacturer's paperwork should confirm the same.
If a door has no identifier and no paperwork, do not assume it is rated. A solid timber door is not a fire door because it looks heavy. It needs to be identified, or surveyed and replaced if it cannot be.
Mistakes that remove the rating
- A leaf trimmed on site beyond the limits in its certification
- A rated leaf fitted into a frame that was never part of the tested set
- Standard hardware swapped in for rated hardware
- Seals painted over or cut out to make a door close more easily
- Holes cut through the leaf for cabling or signage without an approved method
Who is responsible
The Responsible Person for the building must make sure fire doors are the right rating for their position and are kept in working order. This duty comes from the Regulatory Reform (Fire Safety) Order 2005. For how this applies in one sector, see fire door compliance in care homes. For ongoing checks, see our Fire Door Maintenance & Inspection service.