Flat roofing and EPDM

The problem

A flat roof does not stay flat — it should fall gently so water runs off. Older felt roofs pond in the middle, blister in the sun and split at the upstands. Once water sits still on a roof, it finds the weak point.

Most flat roofs in Barry are over a kitchen extension, a bay window or a garage. The common failures are the same: no fall, so water ponds, and tired upstands where the roof meets a wall.

For roofs up to a normal domestic size, EPDM rubber goes down in a single sheet with no joins across the field of the roof, which removes the seams that felt roofs fail at. For larger or more complex roofs we use a hot-air welded membrane or GRP fibreglass.

Whichever system suits the roof, the important part is the same — getting the fall, the trims and the wall abutment right so the water has somewhere to go.

What the job involves

1. Check the existing deck for soft or rotten boards and renew as needed
2. Set the correct fall with tapered insulation or firrings
3. Fit new deck boards where required, screwed not nailed
4. Install single-ply EPDM rubber in one piece where the roof size allows
5. Dress the membrane into new drip trims, and up every upstand and wall
6. Re-flash into the brickwork above with lead or a compatible detail