Garages, kitchen extensions, dormers and porches all over High Wycombe sit under flat roofs, and most of the originals were felt. These are typical 2026 prices for stripping and re-covering them in the three systems we fit.
Typical prices
A single garage or porch costs about £1,000 to £2,500 to strip and re-cover. A single-storey rear extension of 15 to 20 square metres costs about £2,200 to £4,800. Rotten deck boards found under the old covering add to that and are shown to you first.
Firestone RubberCover EPDM
EPDM is a single sheet of rubber membrane with no seams across the middle of the roof. Firestone RubberCover is the system we choose for small residential roofs: garages, extensions, dormers, porches, carports and balconies. It flexes with the building and copes with frost.
GRP fibreglass
GRP is glass-reinforced polyester laid in place to give a hard, jointless finish. It is stronger than felt, takes foot traffic and is easy for a roofer to repair if it is ever damaged. It suits roofs you walk on and neat modern extensions.
Felt
Modern felt systems are the budget option. They are quick to lay and still a sound choice on a garage or outbuilding.
What a proper flat roof quote lists
The strip, the deck (and whether any boards are replaced), the system by name, the edge trims, upstands where the roof meets a wall, the outlet into the gutter, and the guarantee. Every flat roof we fit is fully guaranteed.
Related services
Get a real price for your roof
Ranges are a guide. The real number comes from someone looking at your roof. Pat comes out, shows you what is needed and gives you a free, no-obligation quote.
Questions
How long does a flat roof last?
A well-laid EPDM or GRP roof lasts far longer than old felt. The deck underneath and the detailing at the edges matter as much as the covering.
Can you go over the old felt?
We strip it. Laying over a failed roof traps water in the deck.
How long does a garage roof take?
One to two days for most single garages, weather permitting.