Introduction to Fire Safety Management

potential to reduce the performance as low as 10% of
the required level in many cases, i.e. 3 minutes instead
of 30 minutes. It is critical that the method of installation
and the material and design of the construction
being glazed fully complies with the glass manufacturer’s
recommendations.
Steel sandwich panels
Lightweight sandwich panels are being increasingly used
in buildings; they are often constructed with combustible
plastic core material which is included to provide thermal
insulation. Lightweight sandwich panels combine
the strength of the external material with the insulation
properties of the inner core. Therefore they have become
popular as a building material that enables simple and
rapid erection. Unfortunately this type of panel has been
implicated in the rapid fi re spread and early collapse of
a number of large buildings. It is crucial that any cavities
or concealed spaces that may be created when using
sandwich panels are adequately protected against concealed,
internal fi re spread.
9.4.5 Concealed spaces
Concealed spaces in buildings provide easy routes
for fi re to escape both horizontally and vertically. Fire
cavity
barrier
a. SECTION
wall with cavity
c. PLAN
wall with cavity
compartment floor
cavity barrier
fire-resisting wall
Figure 9.14 The provision of cavity barriers
Fire protection in buildings
spreading in the concealed spaces in a building presents
signifi cant risks due to the fact that it can develop
spread without being detected. Concealed spaces may
also allow a fi re to move through fi re compartmentation.
Access to concealed spaces is always, by their
very nature, limited, therefore, even if a fi re is discovered
before it has developed suffi ciently to affect other parts
of the building, the fi re service is often faced with diffi
culties in bringing it under control.
Concealed spaces are found in numerous locations
in a building including:
➤ Roof spaces
➤ False ceilings
➤ Service risers
➤ Behind decorative panelling
➤ Cavity walls
➤ Floors
➤ Raised fl oors for computer suites.
It is for those reasons that cavities in buildings should
always be provided with barriers that resist the concealed
spread of fi re (see Fig. 9.14). It is particularly
important that cavity barriers are provided at those locations
where the cavity passes through a compartment
wall or fl oor.
suspended ceiling
fire-resisting
wall (but not a
compartment wall)
wall with cavity
b. SECTION
d. PLAN
floor
cavity barrier
alternatively if it is a
compartment wall carry
wall up to underside of floor
cavity barrier
fire-resisting door
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