GRP vs EPDM - Which is better for flat roofs?
Flat roofs are a popular choice for garages, extensions, and commercial buildings in Ireland. But when it comes to waterproofing, two systems stand out: GRP (fibreglass roofing) and EPDM (rubber roofing membrane). Both have excellent performance, but which one is the right choice for your project? Let’s compare their features, benefits, and ideal applications.
What is GRP Roofing?
GRP (Glass Reinforced Plastic), also known as fibreglass roofing, is a liquid-applied system that creates a seamless, joint-free finish once cured.
Advantages of GRP roofing:
- Seamless surface – no joints or overlaps.
- Extremely durable – lifespan of 25–30 years.
- Resistant to water, frost, and UV rays.
- Can be used for walkable surfaces (terraces, balconies).
- Available in different finishes for a neat appearance.
Buildon recommendation: GRP Roofing Kit – a complete package with resin, topcoat, and accessories for professional results.
What is EPDM Roofing?
EPDM (Ethylene Propylene Diene Monomer) is a single ply rubber membrane that is rolled out and adhered to the roof deck. It is widely used in flat roofing because of its long-lasting properties.
Advantages of EPDM roofing:
- Extremely long lifespan – up to 50 years.
- Highly resistant to UV, ozone, and weathering.
- Flexible and easy to install.
- Low maintenance compared to other systems.
- Environmentally friendly – fully recyclable.
Buildon recommendation: EPDM Roofing Membrane – premium rubber roofing sheets designed for the Irish climate.
GRP vs EPDM: Head-to-Head Comparison
| Feature | GRP (Fibreglass) | EPDM (Rubber Membrane) |
|---|---|---|
| Lifespan | 25–30 years | Up to 50 years |
| Durability | Very strong, rigid surface | Flexible, highly resistant |
| Installation | More technical, requires resin & tools | Faster, easier to apply |
| Best for | Balconies, terraces, garages | Large flat roofs, commercial buildings |
| Finish | Seamless, smooth, can be decorative | Uniform black finish |
| Cost | Slightly higher upfront cost | Cost-effective in the long run |
Which One Should You Choose?
- Choose GRP roofing if you want a seamless finish, strong resistance, and a surface you can walk on (balconies, terraces).
- Choose EPDM roofing if you need a long lasting, low maintenance solution for larger flat roofs, garages, or commercial properties.
Conclusion
Both GRP and EPDM are excellent solutions for flat roofs in Ireland. GRP offers strength, a neat finish, and versatility for smaller areas, while EPDM provides unmatched durability and flexibility for large-scale projects.
Explore our full range of GRP Roofing Kits and EPDM Roofing Membranes today at Buildon.ie – with fast delivery across Dublin and nationwide.
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