Civil Engineering Reference
In-Depth Information
refuges (unless the building has no more than two storeys
plus one basement storey, each under 280 square metres
fl oor area).
A refuge:
➤
Should be provided at each point where an escape
route leads into a protected stairway, or an external
stairway
➤
Could be in the stairway, or in a protected lobby or
corridor leading to a stairway. Where two protected
stairways serve a storey, the whole storey could
be effectively divided into two refuges using fi re
resistant walling and doors, giving two alternative
refuges
➤
Could be in the open air on a fl at roof or balcony,
protected by fi re resistant walling and fl ooring as
necessary
➤
Where serving an external stairway, could be exter-
nal, protected by fi re resistant walling as necessary
➤
Should not obstruct the fl ow of other people
escaping
➤
Should be at least 1400 mm
900 mm, and perhaps
larger depending on the number of wheelchair users
it might need to serve.
Escape via an evacuation lift
Lifts should not be used for general evacuation, but they
may be used for the evacuation of disabled people. If
an evacuation lift is provided, it should be designed and
installed in accordance with appropriate standards (BS
8300 and BS EN 8 1-70).
Evacuation lifts are generally placed in protected
stairways. Where they are not in a protected stairway,
there should still be a refuge available.
Figure 9.49
Evacuation chair provided to assist non-
ambulant persons to escape in case of fi re
The management plan of a building should specify the
procedure necessary for carrying disabled people up or
down stairs where this is required. Identifi ed staff should
have this responsibility and be given suitable training for
the task.
9.5.8
Smoke control and ventilation
Protected means of escape including stairways provide
a degree of smoke control within a building. In some
cases it is necessary to provide additional smoke con-
trol to protect vulnerable stairways, for example a single
stairway serving a number of upper fl oors. In this case
it may be enough to provide lobbies at each landing to
reduce the possibility of the stairway becoming smoke
logged. In general there is no need to provide smoke
ventilation in these circumstances; however, there are
some occasions where ventilation is required to protect
the means of escape.
In the case of large buildings with many occupants,
e.g. shopping malls, smoke control and ventilation play a
Figure 9.48
A typical sign indicating a refuge point
Evacuation by stairs
Evacuation of disabled people can take place on any
evacuation stair if:
➤
The stair is not less than 900 mm in width
➤
The stair should be wide enough to manoeuvre a
wheelchair around any bends.
