Our services
Flat Roofing
Any sheet of material used to cover a flat or low-pitched roof is usually known as a membrane and the primary purpose of these membranes is to waterproof the roof area. Materials that cover flat roofs typically allow the water to run off from a slight inclination or camber into a gutter system.
Water from some flat roofs such as on garden sheds sometimes flows freely off the edge of a roof, though gutter systems are of advantage in keeping both walls and foundations dry. Gutters on smaller roofs often lead water directly onto the ground, or better, into a specially made soakaway.
Gutters on larger roofs usually lead water into the rainwater drainage system of any built up area. Occasionally, however, flat roofs are designed to collect water in a pool, usually for aesthetic purposes, or for rainwater buffering.
Traditionally most flat roofs in Edinburgh make use of tar or asphalt more usually felt paper applied over roof decking to keep a building watertight.
The felt paper is in turn covered with a flood coat of bitumen (asphalt or tar) and then gravel to keep the sun’s heat, ultraviolet light and weather off it and helps protect it from cracking or blistering and degradation.
Roof decking is usually of plywood, chipboard or oriented strand board (OSB, also known as Sterling board) of around 18mm thickness, steel or concrete. The mopping of bitumen is applied in two or more coats (usually three or four) as a hot liquid, heated in a kettle. A flooded coat of bitumen is applied over the felts and gravel is embedded in the hot bitumen.
Modern flat roofs can use single large factory-made sheets such as EPDM synthetic rubber, polyvinyl chloride (PVC), thermoplastic polyolefin (TPO) etc.
Although usually of excellent quality, one-piece membranes are called single plies are used today on many commercial and residential buildings.