Chopped strand matCSM

Fibre drawn from molten glass, the most widely used reinforcement for polymer composites. Different formulations, such as E-glass, E-CR glass, S-glass and AR glass, balance cost, strength, electrical performance and chemical resistance. It is the standard reinforcement in GRP laminates, including liquid applied GRP flat roofing systems.

A heavy, coarse fabric woven directly from untwisted glass rovings, usually in a plain weave. It builds laminate thickness and directional strength quickly and is traditionally alternated with chopped strand mat in marine and industrial GRP laminates.

A composite of glass fibre reinforcement in a polymer matrix, most commonly polyester or vinyl ester resin. GRP is widely specified for boat hulls, tanks, enclosures, cladding and cold-applied flat roofing thanks to its corrosion resistance, mouldability and moderate cost.

The degree to which liquid resin has penetrated and coated the filaments of a reinforcement, visible in glass fabrics as a change from opaque white to translucent. Complete wet-out is essential to laminate strength, since dry patches act as built-in defects.

A gelcoat formulated with a wax additive so that its surface cures fully in air, applied by brush or roller as the final coat on GRP surfaces laminated against an open face rather than a mould. It is the standard topcoat on GRP flat roofs and on site-laminated linings and repairs.

An open-mould process in which layers of dry reinforcement are placed in the mould by hand and wetted out with liquid resin using brushes and rollers before curing, usually at ambient temperature. It is the simplest and most widely used method of producing GRP laminates, including site-applied GRP roofing.