The main Flat Entrance Door (FED) to your flat must be a 30-minute fire resisting 'doorset'. A fire doorset is the technical term used to mean the same thing as a fire door, but includes all parts of the door, like the door, the frame, hardware and seals.

There are two types of 30-minute fire doorsets:

  • FD30 fire doors are usually older, original doors that are in good condition. These are built to resist fire for up to 30 minutes.
  • FD30S fire doors not only resist fire but are also able to stop the spread of cold smoke, due to them having smoke brushes in addition to intumescent seals. The S in the rating shows that the door is also smoke resistant.

An intumescent seal is a plastic strip that runs around the door or frame. When it is exposed to heat, it expands and closes any gaps around the door to stop the fire spreading for a period of time.

It is highly recommended that any original door is upgraded to have intumescent strips with cold smoke seals and an intumescent letterbox sleeve fitted.