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Glass Reinforced Polyester (GRP)

What is GRP and why do we use it in Roofing?

Glass fibre reinforcing mat photo

Glass fibre reinforcing mat

Glass Reinforced Polyester (GRP) is, as the name suggests, a polyester material reinforced with the addition of glass fibre (also commonly known as fibreglass). The material is produced by combining thermosetting polyester resin and glass fibres under strictly controlled factory conditions. Glass fibres are applied into the resin with each layer of fibres facing in different directions, enabling the stiffness and strength of the finished material to be controlled. The effect is a strong, lightweight material that is naturally watertight.

The history of GRP

Following the lead of the Egyptians who used glass fibre reinforcement in the fabric of clay jars to stop them breaking during transit, GRP or “Glass Reinforced Polyester” was developed for a wide range of applications by the British military during WW2.

The initial aim was to use GRP for a number of applications such as minesweeping, because of its lack of magnetic footprint. The benefits of GRP were subsequently picked up for use outside of the military in the boat building, motor manufacturing and is now commonplace in the construction industry.

Reasons why you should use GRP roofing products

  • Lightweight and easy to handle
  • Strong and durable
  • Suitable for use in grey water systems
  • Aesthetically pleasing
  • Exceptional detailing capabilities
  • Flexible and versatile
  • Long service life
  • Fire retardant
  • UV resistant
  • Easy to repair
  • Recyclable at end of service life (as long as provided by responsible manufacturer)

Environmental benefits of GRP

As GRP is safe to use in grey water systems and does not emit any chemicals once installed, it is a favoured material for eco-friendly housing and ‘green’ roof waterproofing. This factor is becoming ever important to consider with current move toward ‘greener’ methods and materials. Keeping in mind the bigger picture of a warming environment and the predicted increase in yearly droughts and water shortages.

At the end of its long service life, GRP can be broken down into its component materials, which can then be recycled into new materials, additionally saving the customer money and benefitting the environment.

Risk of theft

The popularity in lead alternatives and indeed alternatives for a wide range of metals is ever growing – theft of these metals continues to be an issue. GRP makes for an ideal alternative for lead and other metals, dependent on the application. GRP also has no scrap value and no value to the thief.

GRP manufacture at Hambleside Danelaw

Hambleside Danelaw has been producing quality roofing products in the UK for over 40 years. We pride ourselves on producing durable and user friendly products that offer long term roofing solutions. Our GRP products are manufactured in our state of the art factories, here in the UK, located in Daventry and Inverness. As a reliable manufacturer, we also offer excellent customer support after the project has finished, and an insurance backed guarantee for peace of mind.

For a healthy roof, use GRP, a durable, versatile, lead alternative material.

Why not take a look at our Dryseal GRP flat roof system and our GRP flashings range for pitched roofing?

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