Fire doors are an essential element in the passive fire protection of buildings. Fire doors help sub-divide a building into compartments, slowing down the spread of fire and allowing occupants to escape. Fire doors and doorsets are rated in minutes and prefixed by the letters FD.
The building regulation relates to the entire door installation, and not just the door alone. Because of this, fire doors are not tested as individual leaves, but as a complete installation, along with frame, locks, latches and other essential ironmongery.
In certain applications, the regulations may state that smoke control is also required as an additional requirement. In these cases the fire door will be designated by the suffix 's' and a combined intumescent and smoke seal must be fitted.
The following table denotes the fire door rating and nomenclature for fire door assemblies:
| Fire Door Rating | Standard Fire Door/doorset | Fire door & Smoke seals |
|---|---|---|
| 30 minutes | FD 30 | FD 30 S |
| 60 minutes | FD 60 | 120 minutes |
| 90 minutes | FD 90 | FD 120 |
| 120 minutes | FD 90 S | FD 120 S |