BS 476-23 Fire tests on building materials and structures — Part 23: Methods for determination of the contribution of components to the fire resistance of a structure

1 Scope

This Part of BS 476 describes procedures for determining the contribution made by components to the total fire resistance of a structure or other elements used in conjunction with them when subjected to the relevant heating and pressure conditions specified in BS 476-20. This Part provides the requirements for specimen selection and/or its design and construction, the edge conditions, the equipment including any special apparatus or instrumentation, and the procedures and criteria as they apply to components which make a contribution to the fire resistance of a complete assembly. The methods are applicable to suspended ceilings protecting steel beams and intumescent seals for use in conjunction with single-acting, latched timber fire resisting door assemblies.

NOTE The titles of the publications referred to in this standard are listed on the inside back cover.

2 Definitions
For the purposes of this Part of BS 476, the definitions given in BS 476-20 and BS 4422 apply, together with the following.

2.1
suspended ceiling

a horizontal membrane and its associated suspension system which is provided below, and not in direct contact with, the structural, unprotected steel beams for the express purpose of protecting them from a fire environment, and which does not incorporate any loadbearing member of the structure

2.2
intumescent seal

a seal comprising material or a combination of materials with the property of swelling or foaming when exposed to heat, intended to improve the fire performance of the element of construction in which it is incorporated