Flat Roof Materials Compared: EPDM, GRP & Felt

If you're planning a flat roof installation or replacement in County Durham, the material you choose will determine how long it lasts, how well it handles our North East weather, and how much it costs. Here's an honest comparison of the three most popular options.

Traditional Felt (Built-Up Roofing)

Felt has been the go-to flat roofing material for decades. Modern torch-on felt systems are a significant improvement over the old pour-and-roll methods, but they still have limitations.

• Lifespan: 10–20 years with good installation
• Cost: Lowest upfront cost of the three options
• Pros: Affordable, proven technology, easy to repair
• Cons: Shorter lifespan, can blister and crack in temperature extremes, vulnerable to standing water

Felt works well for garden buildings, smaller extensions, and budget-conscious projects where you may re-roof in 15 years anyway.

EPDM Rubber

EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane that's become increasingly popular for domestic flat roofs. It's supplied in large single sheets, which means fewer joints and fewer potential leak points.

• Lifespan: 25–40 years
• Cost: Mid-range
• Pros: Excellent flexibility (handles building movement well), UV resistant, handles ponding water, very low maintenance
• Cons: Can look less finished than GRP, requires careful installation at edges and upstands

EPDM is our most recommended option for most domestic flat roofs in Durham and surrounding areas. It handles the North East's freeze-thaw cycles exceptionally well.

GRP Fibreglass

GRP (glass reinforced polyester) creates a seamless, hard-wearing surface that's applied in liquid form and cures to a rigid finish. It's the premium option for flat roofing.

• Lifespan: 30–50 years
• Cost: Highest upfront cost
• Pros: Extremely durable, completely seamless, can be walked on, available in colours, excellent for balconies and walkways
• Cons: Rigid (can crack on timber decks that move), must be installed in dry conditions above 5°C, highest cost

GRP is ideal for areas that will be walked on regularly, or where you want a premium, long-lasting finish. It's particularly good for dormer roofs and balcony areas.

Which Should You Choose?

The right choice depends on your property, your budget, and how long you plan to stay. For most County Durham homeowners, EPDM offers the best balance of cost, longevity, and performance in our climate.

Not sure which option suits your property? Contact us for a free assessment and we'll recommend the best system for your specific situation.

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