The roof is deformed by a large span and affected by external forces. Large public buildings: large span, large space, structural and complex forces, deformation, such as railway stations, memorials and so on. Building roof, especially wood plastic composite sofa for the vast areas of northern China, mainly to solve the problem of insulation and waterproofing, so the roof of the typical structural level is: A. Structural grassroots: mostly prefabricated orifice or cast-in-place reinforced concrete roof. steam layer: to prevent moisture into the insulation layer and set up, mostly a layer of cold base oil or a layer of linoleum.

Insulation: There are two kinds of cast-in-place and prefabricated materials. Commonly used insulation materials are cement perlite, coke residue, aerated timber decking costs south africa coagulation block, polystyrene foam board and so on.

Cement mortar leveling layer E. Waterproof layer: can be a coil, coating and other flexible waterproof layer, it can be fine stone concrete flexible caulking composition of the rigid waterproof layer. protective layer: for flexible roof, in order to prevent premature aging of the waterproof layer, usually in the waterproof layer to add a layer of protective layer, the use of green bean sand, cement brick, brick, light-colored coating or cast-in-place fine stone Wait.

With the development of construction technology in China in recent years, the development of large-span, light and high-rise buildings has greatly increased the deformation of the roof structure, and the appearance of roofs such as parking lots, sports wood plastic composit fence fields and gardens has greatly increased the roof function. Since the eighties, the problem of housing leakage has become a very prominent problem construction.