Last edited 07 May 2019

Glass reinforced plastic GRP

Glass reinforced plastic (GRP), is sometimes referred to as; glass reinforced polyester, fibreglass, glass-fibre reinforced plastic (GFRP), fibre reinforced plastic (FRP) or fibre reinforced polymer (FRP).

It is a composite, laminate material that was first developed in the 1930’s and consists of glass fibres used to reinforce a plastic, typically a polyester resin. The glass fibres can be used as ‘random’ short-chopped strands formed into a mat, or they can be gathered together into ‘rovings’ (bundled rope), or woven into a fabric.

GRP can be mass produced or built-up by hand, and after curing, forms a complex matrix of plastic and glass fibre. The composite properties of high-strength glass fibre and highly-resilient plastic, make GRP strong, lightweight and weather- and corrosion-resistant. It can also be manufactured to be fire retardant. As a result, it is suitable for a very wide range of applications such as boat building, car bodies, cabinets and helmets.

In construction, these characteristics, mean that it is easy to install, requires little supporting structure, is durable and is low maintenance. As a result, it is used to manufacture components such as:

Architectural mouldings.
Fascia panels.
Tanks, planters and linings.
Storage containers.
Doors and door surrounds.
Window surrounds and sills.
Piping.
Cladding panels.
Roofing.
Walkways and railings.
Dome structures such as radomes.
Kiosks.
Covers.
Signs.

It can also be used for temporary applications such as formwork.

GRP can be given a range of colours and textures, as a result of which it is commonly used to re-create the appearance of other materials (such as brickwork) but with a fraction of the weight.

GRP is a fairly brittle material, but is relatively easy to repair when damaged.