Roofs built of corrugated sheets above living quarters in the attic should be ventilated. In the case of roofs with full boarding laid on the rafters, the first stage of covering consists of making full boarding on the rafters and covering the roof with roofing felt in a single layer., sheets parallel to the eaves, without gluing the roofing felt on overlaps, only by nailing it to the formwork with roofing nails (The tar paper contacts remain vapor-permeable). Then, before the onset of winter, counter-battens should be nailed to roofing paper, along the rafters with a thickness of min. 2,0 cm, and make air outlet slots from under the formwork and roofing felt in the roof ridge through the ridge boarding.
In the second stage of roofing, a direct base is made for the roofing of corrugated sheets, nailing the roof years to the counter battens with a spacing appropriate to the slope of the roof. Before nailing the corrugated boards to the battens, pay attention to the proper meshing of the air outlet in the ridge and the inlet to the gap under the roof covering in the eaves. Before laying the first row of corrugated sheets at the eaves, put polyurethane gaskets under the roof covering between the sheet of the gutter strip on the eaves board and the roofing boards. In the case of semi-hard thermal insulation boards, it is better to leave a ventilated gap under the boarding above the thermal insulation with an air inlet in the eaves and an outlet in the ridge.
In the case of roofs’ without formwork on the rafters, in the first stage of roofing, a wind barrier made of vapor-permeable reinforced foil should be placed on them, so called because of the use of plastic reinforcing nets to make it. Wind barrier or the so-called. the second drainage plane should be placed, by unrolling the foil sheets parallel to the eaves, and then fixing it with staples to the upper surface of the rafters. The next foil strips are placed from the eaves strip upwards without gluing, with a bet at least 10 cm. The counter-battens are then nailed along the rafters on the stretched foil. In the second stage of covering, the roofing battens are nailed to the counter battens parallel to the eaves as a direct base for the roofing made of bituminous panels..
Due to the many advantages of corrugated plates, m.in. light weight, easy installation of the cover and low cost, this cover can be used in Poland much more often than before, in accordance with the ITB recommendation in closed buildings and in sheds. Noteworthy is the aesthetic appearance of the roof and resistance to harmful factors’ atmospheric (acid rain in industrialized areas). One of the most important advantages of corrugated sheets is the possibility of using them for renovation of old roofs without the need to remove the old covering., with much lower repair costs than when using traditional covering materials.