Vacuum system for flat roof drainage
In flat roofs drained by the vacuum method, the aim is to completely fill the water drainage pipes. Complete filling is achieved through the use of special roof drains and hydraulic equalization of the installation by appropriately dimensioning the pipes. The energy needed to create the negative pressure is obtained thanks to the difference in the height of the roof drain and the connection point of the negative pressure system to the combined sewage system with a free water table.
Traditional flat roof drainage system
In flat roofs drained using the traditional method, rainwater discharged into the combined sewerage system fills the pipes only partially filled with water.. The degree of filling of rainwater drainage pipes should be maximum 0,7. With this degree of filling, sufficient aeration and venting of the pipelines is guaranteed.
The slopes of the flat roof, enabling effective drainage to the roof drains, are obtained through:
o the slope of the construction layer
for creating a slope in an additional layer under the covering
o variable thickness of the thermal insulation layer.
Thermal insulation boards made of expanded polystyrene or mineral wool forming the slope of the roof, can be cut on computer-controlled machines, thanks to which the required slope and correct arrangement of planes in the corners of the roof are obtained.
Basket and corner edges can run at different angles in relation to the edge of the flat roof. Proper mediation of slope slopes is achieved by arranging slope slabs with a slope parallel to the edge of the slabs or running diagonally.