By Max, Surrey Roofing & Windows Ltd | Updated May 2026
Flat roof replacement cost depends on size, system, insulation, outlets, upstands, rooflights and whether the deck underneath is sound.
System choice matters
GRP fibreglass, EPDM rubber and felt can all work well when installed correctly. The best choice depends on roof shape, foot traffic, detailing, budget and expected lifespan.
Do not ignore the deck
A new membrane over a rotten or poorly drained deck is false economy. The deck, falls, trims and outlets should be checked before pricing the final finish.
Rooflights and lanterns add detail
Skylights and lanterns need properly formed upstands and compatible flashing details. These details affect both cost and long-term leak resistance.
Useful next steps
If you need roofing advice for a Surrey property, start with the relevant service page: roof repairs, emergency roof repairs, flat roofing, roof replacement or roof surveys. We also cover towns including Weybridge, Cobham, Woking, Guildford and Epsom.