Flat Roof Cost Calculator: Felt vs EPDM vs GRP Over 30 Years (UK)
By the Professional Roofers team
Updated 2026 · Independent cost guide
Felt almost always wins on the day-one quote, but a felt roof can need replacing two or three times in the life of one EPDM or GRP roof. This tool compares all three on upfront cost and true cost over the years you plan to stay, so you can see which is actually cheaper for your situation rather than just the cheapest to fit.
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Indicative UK figures: felt £40 to 70/m² lasting ~18 yrs, EPDM £50 to 95/m² lasting ~30 yrs, GRP £80 to 130/m² lasting ~32 yrs. Lifetime cost counts how many times each covering must be renewed within your horizon, plus fixed costs each time. Not a quote.
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