Technical Guidance

What is GRP?

Glass reinforced Polyester, known as GRP, it is produced by combining thermosetting polyester resin and short glass ‘rovings’ cut from continuous filaments.

Today there are a wide range of thermoset resins available for use with various glass fibre materials for all sorts of applications. From boat construction such as lifeboats, minesweepers and luxury yachts where high strength, durability and marine corrosion resistance is required, through to fuel and chemical containment tanks & pipelines; GRP materials find uses everywhere.

Thermoset materials, once cured, have very stable mechanical properties and are generally unaffected by heat unless this is sufficiently high to cause them to char or burn. This gives the characteristic of relatively low rates of thermal expansion and high durability leading to very long service life periods.

To improve the durability of GRP when used in outdoor applications and exposed to UV radiation and weathering, such as rooflights, the life of the material can be further prolonged by the application of a transparent surface protective film.

These characteristics make GRP an ideal product for use in rooflight panels and sheets. Especially where a material is required that can be moulded to match the profiles of the surrounding metal cladding sheets while benefiting from a high strength to weight ratio and extended service life.

To read more on the environmental benefits in using GRP for rooflight manufacturing, you can download the section from our technical manual here. We also have an interesting document, called GRP vs Polycarbonate explaining their differences in rooflight application, view here.

For GRP product information, click here for site-assembled and composite panel or barrel vault rooflight systems. You can continue to explore the technical guide, the next section focuses on natural daylight.