Flat roofing in Leatherhead, Surrey and South West London

Flat Roofs ThatStay Dry.

A single sheet of synthetic rubber, glued down. Fast, flexible, good in the cold, and very good on large simple roofs like garages and outbuildings where a single sheet covers the whole roof.

EPDM is supplied as a single sheet cut to the roof, so a garage or outbuilding roof can be covered with no seams at all. It stays flexible in cold weather and copes with a building that moves. It is less suited to roofs with a lot of detail, where GRP is the better answer.

EPDM is supplied in sheets wide enough to cover most garage and outbuilding roofs in one piece, bonded to the deck with a contact adhesive and finished with metal or GRP trims at the edges. It is the quickest of the three systems to lay and the easiest to walk on for gutter clearing.

Modern high performance felt in two or three layers. Still the right answer on some roofs and the right repair on many existing felt roofs where the deck is sound.

A modern felt roof is three layers, each polyester reinforced and torched to the one below, finished with a mineral cap sheet. It is quick to lay, straightforward to repair and suits garages, sheds and outbuildings, and it is the right repair where an existing felt roof has life left.

Modern reinforced bitumen membranes are laid to BS 8217, in three layers, with a mineral finished cap sheet. Felt is the sensible choice where the roof is small, the deck is sound and the budget matters, and it is the right repair for an existing felt roof with life left.

Blisters, splits, ponding, failed edge trims and blocked outlets. Some flat roofs can be repaired and some are past it. We tell you which, because patching a roof that has water under the covering is throwing money at it.

A repair is worth doing when the deck is sound and the covering has one local fault. It is not worth doing when the roof has been patched before, holds water, or is soft underfoot, because the water is already in the deck. We look, photograph, and tell you which it is.

The report after a flat roof survey says which it is: a local repair with a note of how long the rest of the roof has, or a replacement with the system we recommend and why. Either way you get photographs of the deck and the details, because that is where the decision is made.

Standing water is the enemy of every flat roof. We build in the falls with firrings or tapered insulation and put outlets where the water actually wants to go. Ponding on a new flat roof means someone skipped this.

A flat roof should shed its water within a day of rain. We build the fall into the deck with firrings or tapered insulation, position the outlets where the water goes, and size them for the roof area. It is the least visible part of the job and the part that decides how long the roof lasts.

The code of practice for flat roofs, BS 6229, asks for a design fall of 1 in 40 so the finished roof still sheds water after the deck has settled. We build that in with firrings or tapered insulation and check it with a level before the covering goes on.