Methods of protecting compartmentation

BS 9999:2017 - Fire safety in the design, management and use of buildings. Code of practice

The Building Regulations require that new buildings must be divided into fire compartments in order that the spread of fire in the building be inhibited.

There are obvious areas of weakness, which include doors, windows and ventilation ductwork passing from one compartment to another.

Clause 32.5.2.1 General

Where air handling ducts pass through fire-separating elements such as compartment walls or the enclosures to protected escape routes, then the integrity of those elements should be maintained, using one or a combination of the following four methods:

  • Method 1: thermally actuated fire dampers;
  • Method 2: fire-resisting enclosures;
  • Method 3: protection using fire-resisting ductwork;
  • Method 4: automatically actuated fire and smoke dampers triggered by smoke detectors.

Note 1 These methods are not mutually exclusive, and in most ductwork systems a combination of them will best combat the potential fire dangers.

Note 2 Further information on fire-resisting ductwork is given in the ASFP Blue Book [52] and the ASFP Blue Book (European version) [53].

Fire-resisting ductwork should meet the appropriate fire resistance period for the specific application when tested in accordance with BS EN 1366-1,8,9 and classified in accordance with BS EN 13501-3 and BS EN 13501-4 by a recognised NAMAS/UKAS accredited laboratory.