Best Flat Roof System
A guide to the best flat roof systems available in the UK — comparing EPDM, liquid rubber, GRP fibreglass and felt across durability, cost, maintenance and suitability for different applications.
The flat roof system you choose determines the long-term performance of the building. EPDM, liquid-applied systems, GRP and modern bituminous membranes each have different strengths, detailing requirements and maintenance considerations. Understanding the differences helps you choose the right system for your project, budget and maintenance preference.
Flat Roof Systems Compared
EPDM Rubber Roofing
EPDM is a single-ply synthetic rubber membrane that can often be planned as one large sheet on smaller roofs, reducing field joins. Its flexibility and weather resistance make it a strong option for many residential flat and low-slope roof applications.
Liquid Rubber Coating
Liquid rubber is brush or roller applied as a liquid that cures to form a seamless flexible membrane. Ideal for complex shapes, detailing areas and refurbishment projects where a sheet membrane isn't practical.
GRP Fibreglass
GRP (Glass Reinforced Polyester) creates a rigid fibreglass shell. Hard-wearing but less flexible than rubber membranes — can crack in cold weather or when the roof deck moves. More specialist to install than EPDM.
Felt (Traditional)
Modern bituminous felt systems remain an established roofing option. Suitability depends on the specification, substrate, detailing, installation method and project requirements.
At a Glance Comparison
| Feature | EPDM | Liquid Rubber | GRP | Felt |
|---|---|---|---|---|
| Seams | ✅ None | ✅ None | Has seams | Has seams |
| Flexibility | ✅ High | ✅ High | Low | Low |
| Cold applied | ✅ Yes | ✅ Yes | No | No |
| Service life | Very long | Long | Long | Short |
| Repairability | ✅ Easy | ✅ Easy | Harder | ❌ Poor |
| Complex shapes | Limited | ✅ Excellent | Limited | Poor |
Frequently Asked Questions
What is the best waterproofing system for a flat roof?
Modern flat roofs commonly use EPDM rubber membranes, liquid applied waterproofing systems and spray applied rubber coatings depending on the size and structure of the roof.
How long does EPDM roofing last?
Expected service life depends on the selected EPDM membrane, roof build-up, detailing, installation quality and exposure. Check the current manufacturer documentation and warranty terms for the specific FlexiProof product being specified.
What is liquid roofing used for?
Liquid waterproofing systems are commonly used to seal complex roof details, gutters, balconies and concrete structures where seamless waterproofing is required.
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North West Coverage
Flat Roof Systems Across the North West
Forti Nova supplies EPDM and liquid rubber waterproofing systems across Lancashire, Greater Manchester, Merseyside and West Yorkshire. Visit our Blackburn showroom or call for system advice and pricing.
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