Introduction to Fire Safety Management

Number of escape stairs needed is determined by
the following:
➤ The number of people in the building
➤ Whether independent stairways may be required for
mixed occupancies
➤ Whether a single stair is acceptable – in certain low
rise (and low risk) buildings
➤ Width needed for escape – dependent upon whether
simultaneous or phased evacuation strategies are
employed.
In some larger buildings, additional fi re fi ghting stairs may
be provided for access for the fi re and rescue service.
Protection of escape stairs – escape stairs should
ideally be compartmented (enclosed), providing a
minimum of 30 minutes’ fi re resistance, to ensure that
they can fulfi l their role as areas of relative safety during
a fi re evacuation.
However, it may be possible that an unprotected
stairway (e.g. an accommodation stair) may be used as
an internal escape route to a storey or fi nal exit, provided
that the travel distance and the number of people that
may use it is very limited. This unprotected stairway
should not link more than two fl oors and be additional to
another stair being used for escape purposes; it should
also not be able to compromise a dead-end route.
The provision of fi re rated lobbies or corridors
is used to provide additional protection to an escape
stairway where it is the only stair in a building (or part
of a building) of more than one storey (other than the
ground fl oor) or the staircase extends above 18 m. The
Figure 9.44 Protecting a single staircase
First floor
Fire protection in buildings
provision of lobbies and corridors are also required as
part of phased evacuation strategy.
The protected lobbies or protected corridors should
be provided at each level, except the top storey, including
all basement levels or where the stair is a fi re fi ghting
stair.
A smoke control system may be considered as an
alternative to the provision of any protected lobbies and
corridors.
As in the case of escape routes generally a
protected stairway needs to be free of potential sources
of fi re. Therefore, facilities that may be incorporated in a
protected stairway are limited to toilets or washrooms,
so long as the room is not used as a cloakroom.
A reception desk or enquiry offi ce area at ground
or access level may be included in an escape staircase
enclosure if it is not in the only stair serving the building
or part of the building and is limited to a maximum
of 10 m 2 .
Any cupboards or service riser shafts should be
enclosed with fi re resisting construction.
Special fi re hazards – in the case of a building
containing a special fi re hazard, a protected lobby of
not less than 0.4 m 2 should be provided between the
hazard area and the escape stairway. In addition the
lobby should have permanent ventilation, or a mechanical
smoke control system to protect the area from the
ingress of smoke.
Single staircase – ideally all buildings should have
alternative escape routes and therefore a single staircase
is not an option; however, a single staircase may be
suitable for workplaces of low or normal fi re risk (see Fig.
9.44). In such cases people on each fl oor should be able
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