Fire compartmentalization

The spread of fire can be restricted by sub-dividing buildings into a number of discrete compartments. These fire compartments are separated from one another by compartment walls and compartment floors made of a fire-resisting construction which hinders the spread of fire.

Fire compartmentalization:

Prevents the immediate spread of fire which could trap the occupants of a building.

·      Reduces the chance of fires growing and creating a danger to occupants, fire and rescue services, and people in the vicinity of the building.

·       Limits the damage caused to a building and its contents.

The degree of sub-division that should be provided by fire compartmentalization will be dependent on:

·      The use of the building.

·      The fire load in the building.

·      The height of the building.

·      The availability of a sprinkler system.

Joints between fire-separating elements such as compartment walls or floors, should be fire-stopped to maintain the continuity of resistance; and openings for timber beams, joists, purlins and rafters, and pipes, ducts, conduits or cables that pass through any part of a fire-separating element should be kept as few in number as possible, kept as small as practicable; and should be fire-stopped.

Fire dampers are installed in the ducts of heating, ventilation and air conditioning systems which penetrate fire-resistant constructions and will automatically close on the detection of heat. See Fire damper for more information.

Spaces that connect fire compartments, such as stairways and service shafts, need to be protected to restrict fire spread between the compartments. These are described as ‘protected shafts’.

There are a number of additional requirements depending on the type of building, for example:

·      Parts of a building that are occupied for different purposes should generally be separated from one another by compartment walls and compartment floors.

·      Walls common to two or more buildings should be constructed as compartment walls.

·      Compartment walls in the top story beneath a roof should be continued through the roof space.

·      Walls separating semi-detached houses or terraced houses must be compartment walls.

·      Garages should be separated from attached houses by compartment walls and compartment floors.

·      There are additional requirements for; flats, institutional buildings, other residential buildings and non-residential buildings.