Flat roofs in York, fitted so they don't come back to leak

For most residential extensions and garages we recommend EPDM single-ply rubber. It's a continuous sheet, no joints to fail, lasts 25 to 40 years and is competitive on cost. GRP fibreglass is the right pick where you want a hard wearing trafficable finish or unusual upstand detailing. Felt is the lowest-cost option but the shortest-lived. Lead is the right answer on listed buildings.

A small flat roof up to 15m² runs £600 to £1,000, a medium 15 to 30m² £900 to £1,800, and a large 30m² and up £1,600 to £3,200, in EPDM rubber, felt or GRP fibreglass. The price varies with substrate condition, the number of penetrations, edge detailing and access.

A standard 10 to 15m² garage or extension flat roof is two to three working days for EPDM or GRP. Larger or complex jobs four to six days. Lead flat roofs run two to five days depending on size and detailing.

Twenty-year workmanship guarantee on every flat roof we install, in writing. Manufacturer warranties on top: 20 years on EPDM, 20 to 25 years on GRP, 15 years on felt, 60+ years on lead. Both issued with the final invoice.

Yes, where the membrane is mostly sound and the failure is localised. Patches on EPDM bond with EPDM glue and seam tape. GRP repairs need a fresh laminate over a sanded substrate. Felt repairs are heat-bonded. We're honest at the survey about when repair is sensible and when replacement is the better call.

We install warm-roof systems as standard on any flat roof being replaced as part of a building control notice (heat loss reduction). Sedum and green-roof systems are quoted on the specific design. We'd partner with a specialist supplier for the planting and run the substrate ourselves.

Realistic life expectancies: felt 15 to 25 years; EPDM 25 to 40 years; GRP 20 to 30 years; lead 60 to 100+ years. The variables that matter are the substrate, the falls, the detailing at the upstand and the workmanship at the joints. Cheap install on any of these systems halves the life.