Before commencing work on the installation of the roof covering, it is necessary to check, whether the roof frame is properly assembled (in accordance with the technical documentation). Fixing battens or purlins, constituting the direct basis of the covering, should form an even surface. Then check, whether all angles of the roof slope edges are 90°, small deviations can be corrected with wind braces or other edge treatments (discrepancies cannot be greater than 20-30 mm).
Basic sheet dimensions: a) sheet T-18, b) sheet T-55. The B side of the sheet is called the reverse side and is covered with a protective varnish, but on request it can be covered with decorative varnish.
On a roof with an uninsulated attic, the battens can be attached directly to the rafters (without counter battens) with galvanized nails. Batten spacing depends on the permissible load (carrying capacity) coverage, therefore, it is determined on the basis of technical documentation or manufacturer's recommendations.
Laying metal sheets should start from the eaves, leaving min. 3 cm overhanging the sheet beyond the eaves board. If the corrugated sheets are of different lengths, start with the longest, arranging them from the eaves to the ridge. The angle of the sheet on the roof slope should be checked at least for every fifth sheet. With a roof slope of less than 14° (1 : 4) overlap sheet sealing should be used (contacts) longitudinal and transverse sealing strips made of neoprene rubber.
Fastening the corrugated sheets to the roof structure should be done with fasteners, through the upper sheet folds. In the case of steep roofs, the roofing sheets can be fixed in the lower folds of the sheet, provided that tight washers with neoprene rubber are used under the fasteners. Fastening fasteners should be tightened until torque, until the elastic pad "flows out" (ok. 1 mm) from under the steel washer.