1 Scope
This Part of BS 4255 specifies requirements for the classification, physical properties and marking of
solid (non-cellular) rubber used in preformed gaskets for sealing applications in
buildings where resistance to weathering, ozone and permanent deformation under load
are of prime importance.
This Part applies to chloroprene, butyl, halobutyl, ethylene propylene, chlorosulphonated
polyethylene and silicone rubbers used in the gaskets.
Five classes of material, defined according to the hardness of the rubber, are specified.
NOTE. The titles of the publications referred to in this Part of BS 4255 are listed on the inside back cover.