Steep and flat roofs are used for roofing of buildings, called flat roofs. The flat roof covers the top floor and serves both as a ceiling and a roof. The ceiling is the load-bearing structure, which is usually done horizontally, sometimes over some rooms it can be made with a slight slope. The slopes of the roof slope for water drainage are achieved by using an inclined structure or openwork walls.
Steep roofs are usually structured independently of the floor structure. The roof truss is made of wood, prefabricated reinforced concrete elements or steel sections. Due to the difficulties of transport, assembly and the considerable weight of reinforced concrete elements, the roof truss made of these elements is not often performed. However, where there is a need to build steep roofs, steel or wood is used.
Wooden roofs are widely used in low-rise housing and agricultural construction. Concrete flat roofs are used in multi-family housing.
The flat roof consists of a load-bearing structure, layers of vapor barrier and thermal insulation, the structure or layer shaping the slope and the waterproofing laid on the leveling layer. There are solid flat roofs (closed) with vapor barrier, ventilated and vented.