Common coverings
- Built-up felt: traditional layered bitumen felt; older systems have shorter lives.
- Single-ply membrane (EPDM rubber, PVC): modern, durable sheet systems.
- GRP fibreglass: a seamless, rigid finish.
- Mastic asphalt and liquid coatings: used in various settings.
Common problems
- Ponding: standing water where falls are inadequate, accelerating deterioration.
- Blistering, splitting or cracking of the covering.
- Failed upstands, flashings and junctions with walls, a very common leak point.
- Blocked outlets and gutters causing water to back up.
How long should they last?
Lifespan depends heavily on the system and the quality of installation. Older felt roofs may last only ten to twenty years, while well-installed modern EPDM or GRP systems can last considerably longer. Regular inspection and keeping outlets clear make a real difference.
Advice
If you are buying a property with a significant flat roof, or yours is showing any of the signs above, an inspection will establish its condition, remaining life and the cost of any repair or replacement, before a small problem becomes an expensive one.