Felt roofing in Leatherhead, Surrey and South West London

Felt, Laid inThree Layers.

A vapour control layer, an underlay and a cap sheet, each torched and bonded to the one below with the laps staggered. One layer of felt is a temporary roof. Three, laid to a fall, is a proper one.

The vapour control layer stops moisture from the room below getting into the roof. The underlay gives the roof its strength. The mineral cap sheet takes the weather. Each is torched to the one beneath with the joints staggered, so no seam runs through the whole thickness.

The three layers are laid with the laps staggered and torched so the bitumen flows at each lap, then rolled, with the edges dressed into a drip trim at the gutter and up an upstand at any wall. A typical garage roof takes a day, an extension roof one to two.

A split lap, a blister or a puncture on an otherwise sound roof can be cut out and patched with new membrane torched in. We do it where the rest of the roof has life left, and say so when it has not.

A local repair on a felt roof is a proper patch: the damaged area cut out, the deck checked and dried, and new membrane torched in with generous laps. Done on a sound roof it lasts; done over a wet deck it does not, which is why we check first.

A felt repair is cut back to sound membrane, the deck checked and dried, and new cap sheet torched in with laps of at least 100 millimetres. Where the roof has several failures, or the deck is soft, the repair is not worth doing and we say so.

Blisters mean water or air is trapped under the membrane. Splits at the laps and edges mean it has moved or aged. Ponding means the deck no longer falls to the outlet. Each tells us how much of the roof is still doing its job.

Blisters mean trapped moisture. Splits along the laps mean the roof has moved or the bond has failed. Ponding means the falls have gone or the outlet is blocked. One of these on an otherwise good roof is a repair. All three together mean the roof is done.

Ponding is the one to watch: water standing more than a day after rain is finding its way into the laps, and by the time it shows inside the deck is often already wet. A survey visit tells you whether the falls can be restored or the roof needs rebuilding.

A felt roof on its third patch is usually cheaper to replace than to keep repairing, and we will tell you plainly when that point has come. Often the answer is a new felt roof; sometimes it is GRP, and we quote for whichever suits the building.

Each patch is a new set of laps to fail, and the deck under an old felt roof is often already damp. When repairs are being made every year, the money is better spent on a new roof, and we will show you the photographs that make the case.

A felt roof that is more than fifteen to twenty years old and on its second or third repair is usually at the point where a new roof costs less over five years than continuing to patch. We show you the photographs and the itemised price and you decide.

Felt is quick to lay, easy to repair and suits garages, sheds and outbuildings. GRP is seamless and suits extensions and dormers. EPDM suits large simple roofs. We fit all three and recommend by roof, not by habit.

We are not tied to one system. The recommendation comes from the size of the roof, how much detail it has, whether it will be walked on, whether it is seen from above and what it is over.

The quote sets out the system we recommend for your roof and, where two would work, both prices, so you can choose between them with the facts in front of you rather than on our say so.