Fire-stopping 

9.24 In addition to any other provisions in this section, both of the following conditions should be met. 

a. Joints between fire-separating elements should be fire-stopped.

b. Openings through a fire-resisting element for pipes, ducts, conduits or cable should be all of the following.

As few as possible.
As small as practicable.
Fire-stopped (allowing thermal movement in the case of a pipe or duct). NOTE: The fire-stopping around fire dampers, fire-resisting ducts, fire and smoke dampers and smoke control ducts should be in accordance with the manufacturer or supplier’s installation instructions.
9.25 Materials used for fire-stopping should be reinforced with (or supported by) materials rated class A2-s3, d2 or better to prevent displacement in both of the following cases.

a. Where the unsupported span is greater than 100mm.

b. Where non-rigid materials are used (unless subjected to appropriate fire resistance testing to show their suitability).

9.26 Proprietary, tested fire-stopping and sealing systems are available and may be used. Different materials suit different situations and not all are suitable in every situation. 

9.27 Other fire-stopping materials include the following. 

a. Cement mortar.

b. Gypsum-based plaster.

c. Cement-based or gypsum-based vermiculite/perlite mixes.

d. Glass fibre, crushed rock, blast furnace slag or ceramic-based products (with or without resin binders).

e. Intumescent mastics. These may be used in situations appropriate to the particular material. Not all materials will be suitable in every situation.

9.28 Guidance on the design, installation and maintenance of measures to contain fires or slow their spread is given in Ensuring Best Practice for Passive Fire Protection in Buildings produced by the Association for Specialist Fire Protection (ASFP). 

9.29 Further information on generic systems, their suitability for different applications and guidance on test methods, is given in the ASFP Red Book.