Cost guide
Flat Roof Cost UK: EPDM, GRP & Felt Compared (2025)
Modern flat roofs last 20–50 years when installed properly. Here's what each system actually costs and where it makes sense.
The numbers
Typical UK price ranges
| Item | Typical range | Unit |
|---|---|---|
| EPDM rubber | £80 – £120 | per m² |
| GRP fibreglass | £90 – £140 | per m² |
| Torch-on felt | £60 – £100 | per m² |
| Garage flat roof | £1,200 – £2,800 | total |
| Extension flat roof | £1,800 – £4,200 | total |
Guide prices — every job is different. Your fixed written quote comes after a free survey.
What moves the price
Factors that change the number
- System choice — EPDM is usually best value long-term
- Decking condition (replacement adds £25–40/m²)
- Warm-roof insulation upgrades
- Edge trims & outlets
- Access
Questions
Common questions
Modern torch-on felt is far better than the old stuff, but EPDM usually beats it on lifespan and price per year.
Get your exact figure — free
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