3.12.1 General provision
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Explanations & Illustrations
Clause 3.12.1. : General provision
Figure 3.12.1 : Fire stopping to a pipe in a compartment wall
Fire stopping is concerned with ensuring that the fire-resisting capability of a component, i.e. separating wall, compartment wall/floor, cavity barrier is not diminished or impaired when penetrated by services for example, a pipe, ducts, etc..
Therefore whenever gaps are created by the penetration of such pipes, ducts in the fire-rated wall/floor, they must be kept as few as possible. The spacing and internal diameter of pipes passing through any elements of structure or cavity barrier
shall comply with Cl.3.9.3 and Table 3.9A.
Openings for pipes, ducts, conduits or cables which pass through any part of a compartment (except for a part which does not serve as a fire resisting barrier) or cavity barrier, shall be:
a. kept as few in number as possible;
b. kept as small as practicable; and
c. all gaps shall be filled with fire-stopping materials.
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Rationale - Clause 3.12.1c
Fire-stopping materials will ensure the integrity of the fire compartment is maintained when penetrated by utility lines or pipes.
Materials for fire stopping shall have the necessary fire resistance when tested to BS 476: Part 20 or other acceptable standards.
3.12.3 Materials for fire-stopping
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Explanations & Illustrations
Clause 3.12.3 : Materials for fire stopping
( No illustration )
To prevent displacement, materials used for fire stopping should be reinforced with (or supported by) materials of limited combustibility in the following circumstances:
a. in all cases where the unsupported span is greater than 100mm, and
b. in any other cases where non-rigid materials are used (unless they have been shown to be satisfactory by test)
Preference should be given to proprietary fire stopping and sealing system.
When cement mortar or gypsum board plaster or cement or gypsum based vermiculite/perlite mixes is used as fire stopping material, care should be exercised to ensure that workmen properly fill up the entire gaps with the appropriate fire stopping material instead of carrying cosmetic application by just filling up the gaps superficially.
Suitable fire-stopping materials include:
a. Fire-stopping and sealing systems (including those designed for service penetrations) which have been shown by test to maintain the fire resistance of the wall or other element.
b. Other fire-stopping materials include:
(1) cement mortar;
(2) gypsum-based plaster;
(3) cement or gypsum-based vermiculite/ perlite mixes;
(4) glass fibre, crushed rock, blast furnace slag or ceramic based products (with or without resin binders); and
(5) intumescent mastics.
The method of fire-stopping and choice of materials shall be appropriate to the situation and its application.
