GRP Roofing System
Durable, waterproof GRP roofing systems for flat roofs of all sizes.
Specialists In GRP Roof Installation
At On Site Coatings, we are experts in GRP roof installation, delivering high-quality solutions that protect and enhance flat roofs of any size. From complex commercial flat roofing systems to balcony areas, our team specialises in creating seamless, long-lasting waterproofing systems tailored to your needs. With over 20 years of experience, fully accredited teams, and trusted by leading brands such as Amazon, Next, Aldi, and Jaguar, we pride ourselves on reliability, quality, and customer satisfaction.
How Does GRP Waterproofing Work?
GRP, or Glass Reinforced Plastic, is a tough, composite material combining fibreglass matting with a waterproof resin. This creates a seamless layer that completely protects your roof from water ingress.
Unlike traditional roofing systems, GRP has no joints or seams, meaning water cannot seep through. Once bonded to your roof substrate, it forms a permanent protective skin that not only waterproofs but also resists UV exposure and withstands temperature changes. This makes it an ideal solution for flat roofs, balconies, and other areas requiring durable, low-maintenance waterproofing.
Quick, Reliable & Long-Lasting Waterproofing
Our GRP roofing process is designed to be efficient, reliable, and fully transparent. Here’s what you can expect when working with On Site Coatings:
- 1. Prepare the surface: We clean, dry, and prime your roof, repairing any defects, cracks, or blisters to ensure a flawless base.
- 2. Fibreglass mat is laid: The mat is cut to size to seamlessly cover corners, edges, and upstands.
- 3. Resin is applied: Resin saturates the fibreglass, bonding it to the substrate to form a strong, waterproof layer.
- 4. Repeat if needed: Depending on your roofing specification, we may add extra layers for durability, with full guidance on what you need.
- 5. Finish with a topcoat: Choose from UV-stable, coloured, slip-resistant, or extra-protective topcoats to achieve your desired finish and performance.
We Price Match Like-For-Like Quotes
Contact us today to discuss your project in more detail.
Book your FREE site survey today!Highly Recommended, Experienced GRP Roofing Contractors
As one of the UK’s leading coating application specialists, On Site Coatings is proud to work with some of the country’s most recognised brands. Our customers continue to recommend us because of our consistent quality, reliability, and professionalism.
Trusted by Leading Brands We are proud to deliver projects for Amazon, Next, Aldi, Jaguar, and many more, proving our reliability and quality on every site.
Dedicated Project Management Every project has a qualified supervisor on site daily, ensuring work is completed to the highest standards with daily signed reports for full transparency.
Guaranteed Peace of Mind All GRP roofing projects come with a 10-year warranty, backed by our expertise, manufacturer approvals, and strong industry relationships.
Frequently Asked Questions
What our clients say
about us?
Beyond Expectations!
We needed a reliable solution for our leaking flat roof, and On Site Coatings delivered beyond expectations. From the survey to the handover, the team were professional, punctual and kept us updated every day with progress reports. We’d happily recommend them to anyone looking for a good quality roofing partner that makes the entire process hassle-free.
January 2026