What is GRP?

GRP stands for Glass Reinforced Plastic , more commonly known as Fibreglass– a highly resilient and long-lasting material used in many sectors of industry including roofing for balconies, extensions, orangeries , garages, and flat roofs throughout the UK.

It was initially used for boat building because of its strength, waterproof properties and the fact it does not corrode in water. These benefits make it a perfect roofing material, especially in the UK where the main challenge for roofers is creating a waterproof roof with material that lasts in the wet weather.


How Do You Install a GRP Roof?

A GRP/fibreglass roof is made up of 5 distinct layers.





1.Quality Board

The OSB3 decking creates a base with no knots or voids to avoid bubbles or imperfections in the upper layers. This base is designed with a slight incline to ensure that rain and excess water runs off into a drain or gutter rather than pooling on your roof.

All required preformed fibreglass edge trims are attached. There are a multitude of trims to cater for every eventuality, or, with our expertise can tailor the fibreglass to suit any contour whilst still ensuring the whole roof will remain one complete watertight unit.

All joints corners etc are reinforced first with an initial layer of fibreglass mat or very strong fibreglass woven tape.

2. GRP Fibreglass

The GRP roof itself is a single-ply GRP laminate reinforced with CSM (Chopped Strand Mat) – this is the tough fibreglass layer.The whole roof is then laminated with the fibreglass mat and high quality polyester roofing resin .The addition of the catalyst to the resin at a specific ratio dependant on the ambient temperature will ensure the material goes off/hardens to provide a highly durable watertight membrane.More layers can be added if required.

3. Pigmented Topcoat

Finally, the topcoat is applied to the laminate, this provides a UV stable thixotropic pigmented primary waterproof layer. the standard colour is a dark grey , but any colour is available upon special request to suit your individual needs.

It is most important to check and verify the installers credentials prior to appointing them. Anyone can go on the manufacturer’s training course to gain a certificate but this does not give them the required level of experience to provide you with a high quality faultless roof. We have over 30 years’ experience in the industry, and have also been retained by large building firms to provide consultation and on going training of there staff.

What are the Benefits of GRP Roofing?

The main benefits of GRP roofing is the longevity of the roof and watertight properties of the fibreglass. Our roofs come with a 25 year transferable guarantee, but the roof itself will last much longer than that.

The material is so watertight that it’s used to build a wide variety of boats ,yachts, canoes, bathtubs etc,in fact it is suitable for many sectors of industry where a 100% waterproof /durable membrane is required  – once the roof is finished it creates a fully sealed surface with no seams, joins, or weak points for water to penetrate.

Lead and copper roofs are associated with toxic water runoff, but GRP roofs are environmentally friendly and don’t require heat to install . The resilience and low scrap value even deters criminal damages and improves your home security.

If your roof gets foot traffic (like most balconies or some garage roofs), we can add a non-slip texture with no impact on longevity or overall strength.

Is GRP Roofing Suitable for My Property?

A GRP roof is suitable for any flat roof area on any property, it can also be installed on pitched or curved/domed surfaces, balconies/terraces etc. It’s the perfect choice if:

  • You’re concerned about longevity, and want a problem-free,guaranteed roof for at least 25 years
  • You would like to replace your bitumen, felt, or lead roof
  • Your roof has a walkway or gets foot traffic
  • You live in an area with a lot of rain
  • You would like to add an unusual colour to your roof
  • You have a complex roof shape, with roof lights or domes
  • You want a maintenance-free option

If you’d like a new roof with a 25 year guarantee, get in touch. We offer bespoke colours and fast, efficient installation done by qualified and accredited,highly experienced friendly people in any part of the UK or world as materials can be shipped anywhere.