GRP Product Line Inverness

Part of our product development process involves selecting the most suitable material and appropriate formulations for the intended application. We use Glass Reinforced Polyester (GRP) and polypropylene for many of our products, due to their qualities and environmental credentials.

GRP is used for our flat roofing system, Dryseal, and also for many of our flashing products in the Pitched Roofing division, supplying a wide range of solutions for the slate and tile roof market. The material is chosen for its stable mechanical properties, durability, strength and longevity which also makes it perfect for our Zenon range of rooflights. Read more about GRP, it’s history and why it is ideal for a range of roofing products.

Being lightweight and flexible, polypropylene is the ideal material for some of our smaller pitched roofing products. It is a versatile and durable thermostatic polymer with a wide service temperature range and reduced environmental impact compared with the commonly used alternatives; read more about polypropylene in the next section of the website.

The polypropylene is formed into products either by injection moulding or extrusion. Our factory in Daventry is home to many injection moulding machines that work by injecting liquid polypropylene material into moulds, before cooling the molten plastic to form the strong and resilient product.

Extrusion is the process of moulding the plastic into a fixed cross-sectional shape. The polypropylene is pushed through a die of the desired cross-section. This forms the product, and gives it a smooth surface finish.

For more information on our materials and our methods of production, you can get in touch via