Flat roofing
Flat roofs that finally stay dry.
Single-ply, EPDM and GRP flat roofs for extensions, garages, dormers and balconies, with the upstands, outlets and edges detailed so water has nowhere to sit.
- Systems
- Single-ply PVC/TPO, EPDM, GRP
- Insulation
- Warm-roof upgrades available
- Typical job
- 1–3 days for an extension
- Guarantee
- Up to 20 years on qualifying systems
Most flat roofs fail at the details
The membrane in the middle of a flat roof rarely lets water in. The leaks start at upstands, drip edges, outlets and joints to walls. That’s where we spend our time.
We’ll recommend the system that suits the roof, the budget and how the space is used, and explain why.
Our work
How we build a flat roof
Deck
Rotten boards replaced with new OSB3 or plywood; falls corrected so water drains.
Insulation
Optional warm-roof build-up to bring older extensions up to current thermal standards.
Membrane
Single-ply, EPDM or GRP laid by our own trained installers, never subcontracted.
Edges & upstands
Proper trims, upstands at least 150mm and lead or membrane cover flashings.
Outlets
Outlets and gutters sized for the roof area, with leaf guards where trees overhang.
Time to replace a flat roof?
- Ponding water that sits for days
- Blisters, splits or cracking felt
- Spongy or soft areas underfoot
- Damp on the ceiling below
- Moss or plants growing on the roof
- Felt more than 15 years old
| System | Finish | Lifespan | Good to know |
|---|---|---|---|
| Single-ply PVC / TPO | Clean, light grey | 25–30 years | Hot-air welded seams; ideal for larger and commercial roofs |
| EPDM rubber | Matt black | 20–30 years | Laid in one sheet on most domestic roofs, very few joints |
| GRP fibreglass | Seamless, can be coloured | 20–25 years | Rigid and walkable; great for balconies and dormers |
Can you go over my old felt roof?
Occasionally, but usually not. Overlaying traps moisture and hides a failing deck, so we normally strip back and check the boards first.
Can you insulate the flat roof at the same time?
Yes. A warm-roof upgrade adds insulation on top of the deck and is the ideal time to improve an older extension.
Is a flat roof guaranteed?
Our workmanship is guaranteed in writing, and many membrane systems carry a manufacturer guarantee when installed by an approved contractor.
Other roofing services
Free quotes
Get a price for your flat roofing.
Start with your postcode and the job. We’ll take it from there.
Free roof health checks across Seaham, Sunderland, Durham and the coast.