Flat Roofing

Felt, GRP and single-ply systems for extensions, garages and dormers

Flat roofs cover a lot of ground that pitched roofing never touches — extension roofs, garages, dormer tops, porches — and they fail in their own particular way, through standing water and membrane movement rather than slipped tiles.

A flat roof is never actually flat — it's laid to a shallow fall, typically toward a gutter or outlet, so that rainwater runs off rather than sitting on the surface. When that fall is wrong, or when the waterproof membrane itself has aged, cracked or lifted at a joint, water pools and eventually finds its way through. We work with the common flat roof systems found on this kind of property: torch-on or pour-and-roll felt systems, GRP (fibreglass) roofing, which forms a single seamless waterproof layer, and single-ply membrane systems for larger areas. Each has a different lifespan and a different failure pattern, and the right choice depends on the size of the roof, how it's accessed, and what sits above and below it — a dormer roof on a loft conversion has different requirements to a single-storey extension roof that might later be walked on. Installation starts with the deck itself: checking or replacing the timber or board substrate, getting the falls correct so water actually runs to the outlet, then applying the chosen membrane with properly detailed upstands, edge trims and outlets, since most flat roof failures start at a joint or an edge detail rather than in the middle of the flat surface.