Civil Engineering Reference
In-Depth Information
Backdraught
- an explosive reaction that occurs
when a fi re in an enclosed space, which has died down
due to insuffi cient oxygen, is provided with large quan-
tities of oxygen.
Fire compartment
- a building or part of a building,
comprising one or more rooms, spaces or storeys,
constructed to prevent the spread of fi re to or from
another part of the same building.
Dead-end
- an area from which escape is only
possible in one direction.
Inner room
- a room that can only be accessed
through another room.
Storey exit
- an exit that provides egress from a
compartment fl oor into a protected stairway or fi nal exit.
Protected route
- a corridor or stairway that is
separated from the rest of the building by a minimum
degree of fi re resistance (normally 30 mins) and is a 'fi re
sterile' area, i.e. contains no ignition sources or combust-
ible material. A protected route will contain or lead to a
fi nal exit.
Final exit
- a door that gives access to a place of
ultimate safety outside the building.
installation will detect heat or combustion products of a
fi re in its early stages and raise the alarm. Such systems
should be monitored remotely when the building is not
occupied to allow the fi re brigade to be summoned with-
out delay, thus reducing the damage. A sprinkler installa-
tion will release water from the heads nearest the fl ames
with fl ow switches raising the alarm in a similar way to a
conventional detection system.
Active systems also include those that assist in
compartmenting the fi re such as fi re door release
mechanisms, fi re shutters and mechanical damping
systems. In addition other systems may be actively used
for smoke extraction.
Neither passive nor active fi re protection measures
can be installed and then forgotten; they require regular
inspection and maintenance. Service contracts should
be established with accredited contractors for installed
equipment but the fi re safety manager should also
ensure that regular inspections are made of escape
routes, fi re doors and housekeeping standards and that
suitable records of such inspections are kept.
9.3
Legislative requirements
9.2
Fire protection (preventive and
protective measures)
The design and construction of buildings in the United
Kingdom must achieve reasonable standards of fi re
safety and resistance from a fi re starting inside the
building or a fi re spreading from outside the building.
In addition, all buildings must be designed and con-
structed in a way that protects the occupants from the
fi re and ensures their safe evacuation. In England and
Wales the legal requirements are set out in the Building
Regulations 2000 (as amended 2006) and the Building
Regulations (Scotland) 2003 for Scotland.
Fire protection of buildings, the preventive and protect-
ive measures that will protect persons in the event of a
fi re, fall into two broad categories referred as passive
and active protection.
9.2.1 Passive fi re protection
Passive fi re protection is based on the principle of contain-
ment; the compartments of the building are constructed
so that if a fi re should occur, it will be restricted to one
area. For example, fi re doors should prevent the spread of
smoke and fl ames from lobbies, stairwells and lift shafts.
Another example of passive fi re protection is the
design of escape routes, which should not incorporate
combustible wall, ceiling or fl oor linings. Fire dampers
should be installed in ducts where they pass through
compartment walls, and holes in such walls around
cables and other services should be fi re stopped.
Doors and shutters in compartment walls should be
able to withstand the effects of fi re for the same period
of time as the walls themselves.
9.2.2 Active fi re protection
Active fi re protection systems may detect or extinguish a
fi re, with a water sprinkler or inert gas fl ooding installation
performing both functions. An automatic fi re detection
Figure 9.2
Front cover of Approved Document B
