Gasket ~ an alternative to using mastic or sealant to close the
gap between two cladding panels. They are used specifically where
movements or joint widths are greater than could be
accommodated by sealants. For this purpose a gasket is defined in
BS 6093 as, `flexible, generally elastic, preformed material that
constitutes a seal when compressed'.Location and fit ~ as shown on the next page, a recess is provided in
at least one of the two adjacent claddings. To be effective contact
surfaces must be clean and free of imperfections for a gasket to
exert pressure on adjacent surfaces and to maintain this during all
conditions of exposure. To achieve this, greater dimensional accuracy
in manufacture and assembly of components is necessary relative to
other sealing systems.Profile ~ solid or hollow extrusions in a variety of shapes.
Generally non-structural but vulcanised polychloroprene rubber can
be used if a structural specification is required.Materials (non-structural) ~ synthetic rubber including neoprene,
silicone, ethylene propylene diene monomer (EPDM) and thermo-
plastic rubber (TPR). These materials are very durable with
excellent resistance to compression, heat, water, ultra-violet light,
ozone, aging, abrasion and chemical cleaning agents such as
formaldehyde. They also have exceptional elastic memory, ie. will
resume original shape after stressing. Poly vinyl chloride (PVC) and
similar plastics can also be used but they will need protection from
the effects of direct sunlight.Refs.BS 4255-1: Rubber used in preformed gaskets for weather exclusion
from buildings. Specification for non-structural gaskets.BS 6093: Design of joints and jointing in building construction.
Guide.Concrete Cladding--Gasket Joints