Back to glossary

GRP roofingGRP

A cold-applied roof waterproofing system in which glass fibre reinforcement, usually chopped strand mat, is laminated in situ with catalysed unsaturated polyester resin over a suitable deck, then finished with a pigmented topcoat. It produces a seamless, rigid covering commonly used on domestic flat roofs, valley gutters and preformed edge trims.

Also known as: fibreglass roofing, glass-reinforced plastic roofing

Related terms

Chopped strand mat

CSM

A non woven glass reinforcement made from chopped strands distributed randomly and held with a powder or emulsion binder that dissolves in styrene based resins. It gives roughly equal in plane properties in all directions, wets out readily by hand lay up and is the standard reinforcement in GRP flat roofing laminates. It is specified by areal weight.

Composites & laminatesReinforcements & fibresRoofing & waterproofingConstructionMarineIndustrialAutomotive

Unsaturated polyester resin

UPR

A thermosetting resin dissolved in a reactive monomer, usually styrene, that cures by free-radical polymerisation when initiated with an organic peroxide such as MEKP. It is the workhorse matrix for glass-reinforced plastic in boat building, GRP roofing, tanks and vehicle panels, offering low cost and straightforward processing.

Resins & adhesivesComposites & laminatesRoofing & waterproofingAutomotiveConstructionMarineGreen energyIndustrial

Gelcoat

A pigmented, resin-rich surface coat applied to the mould face before laminating, which cures to form the smooth, weather-resistant outer surface of a GRP moulding. It protects the underlying laminate from moisture and UV exposure and provides the colour and gloss of the finished part.

Composites & laminatesCoatings & protectionMarineConstructionAutomotiveIndustrialGreen energy

Liquid-applied waterproofing

Waterproofing formed in situ by applying a liquid resin, typically polyurethane, polymethyl methacrylate (PMMA), unsaturated polyester or a bitumen-based formulation, by roller, brush or spray, which cures to a seamless elastomeric membrane. Often reinforced locally or throughout with a fleece, it is particularly suited to complex details and refurbishment over existing coverings.

Roofing & waterproofingCoatings & protectionConstructionIndustrial

Glass fibre

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.

Reinforcements & fibresComposites & laminatesRoofing & waterproofingMaterials science (general)AerospaceAutomotiveConstructionMarineGreen energyIndustrial

Ready to start?

Create an account to browse and specify, or schedule a consultation to talk through your project with one of our specialists.

Schedule a consultation

Arrange a call with a specialist to discuss your application.

Choose a time

Browse the catalogue

Explore the full range of advanced materials and systems.

View products