The most durable version of a ventilated flat roof is a two-part man-made flat roof. Access to the ventilated part enables periodic inspections of the technical condition of the flat roof and easy repair of any damage.
Flat roofs are flat roofs, in which the height between the ceiling and the roof is several dozen centimeters. In flat roofs, the distance between the ventilation openings may be 25 – 30 m. These openings are made on opposite parapet walls. In halls with a width above 30 m, ventilators should be placed on the roof (at intervals not greater than 25 m) in such quantity, to on 1 m² of roof fell 5 cm2 of the vent cross-section.
The construction of a split roof can be made of wooden trusses and installed between masonry attic walls. It is a much lighter and more economical structure than a heavy flat roof with openwork brick walls. The sheathing is made of waterproof plywood, on which the waterproof layer is a bituminous underlayment and a heat-weldable roofing felt. All roofing felt layers are folded over the external parapet walls and secured with a concrete element or flashing.
Thermal insulation made of glass or rock wool is spread over the entire surface of the ceiling, between construction elements. Under the insulation, there is a vapor barrier made of roofing felt, which is also a foundation for the wooden foundations supporting the structure of the flat roof.
Another solution is a two-piece flat roof with external drainage with a light wooden structure based on a full ceiling closing the last floor.
• Belki podwalinowe wysunięte poza lico ścian zewnętrznych tworzą szeroki okap z widocznymi belkami,
• Krokwie kształtujące spadki połaci oparte są u dołu na przebiegającej po obwodzie stropodachu płatwi stopowej a w części wyższej na słupkach ustawionych na podwalinach.
• Thermal insulation made of wool is placed on the ceiling between the ground beams.
• Wentylacja stropodachu odbywa się poprzez kratki nawiewne zamocowane pomiędzy krokwiami.
• Orynnowanie założone jest przy uskoku utworzonym przez końce krokwi, and the eaves themselves are finished only with sheet metal fittings.
The presented solution can be easily modified by changing the covering material, slope angle and changing the dimensions and details of the eaves.