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Guidance where upgrading the fire resistance of existing doors to protected
stairs.
The approved document to regulation B1 requires FD20 doors to all habitable rooms in a new or
altered dwelling houses with one floor more than 4.5m above ground level, where they form part of
the enclosure to the stair.If there is desire to retain existing doors within a dwelling house, when
undertaking alterations to form habitable rooms, with one floor more than 4.5m above ground level
the following may be considered as suitable alternatives to replacing some or all doors.
General provisions
1. In addition to smoke detectors at every storey level, detectors should also be provided at half
landing levels adjacent to habitable rooms. A heat detector should be provided in the kitchen
and smoke detectors in all habitable rooms entered from the stair enclosure. All alarms should
be mains powered with standby battery backup, interlinked so that detection of heat or smoke in
one unit operates the alarm in all others.
2. BS 5839:6 recommends optical smoke detectors in circulation areas with ionization detectors
better for living and dining rooms. Optical may be better in bedrooms although either type
would be considered acceptable.
3. There should be at least one window at first floor level of a size that would permit emergency
egress to either a rear garden of sufficient depth or to the front elevation. Window to be a
minimum size 0.450m x 0.450m equal to 0.33m2 with a sill height between 0.800 and
1100mm above floor.
Panel doors in excess of 32mm thickness
1. The door should be attached to the door frame with steel hinges, not be visibly warped, fits well
into its frame and there should be no visible defects particularly in the panels.
2. Any existing glazing to doors or fanlights should be replaced with wired glass or similar fire
resistant glazing to provide adequate resistance for integrity and stability.
3. There should be no significant defects to adjacent walls or around door frames forming the stair
enclosure.
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