EPDM vs GRP Flat Roofing

Every comparison depends on the existing structure, the surrounding properties, and how long you'll hold the building. We'll tell you on the survey, in writing, which we'd specify and why.

The deciding factors are the shape of the roof and what happens on it. A simple rectangular garage or dormer with no foot traffic suits EPDM: the membrane arrives as a single sheet sized to the roof, so there are no seams to fail. A roof with lots of corners, upstands, rooflights or pipe penetrations suits GRP, because the system is formed wet on the deck and every trim is part of the same seamless skin. Where a deck doubles as a balcony or walkway, GRP takes the foot traffic better; where the roof is large and simple, EPDM usually comes in cheaper per square metre. We fit both, so the recommendation is based on the roof, not on what we have in the van.