If the roof angle does not exceed ten degrees, then the crate is solid, and the overlap will be up to thirty centimeters. With an angle of ten to fifteen degrees-the crate to forty-five centimeters is sparse, and the overlap reaches twenty centimeters in one wave. A slope of about fifteen degrees — up to seventeen centimeters overwhelming, and crate — not more than sixty centimeters. The bars of the crate are placed on the rafters. Ondulin is cut with an electric saw or hacksaw, while the canvas is lubricated with oil. Lay the sheets from the bottom up, fixing in every wave at the ends and side overlains. Yends are issued using special skating elements. Roof ribs are decorated with tongue or skating elements. The waves occur on the crest exclusively during the installation of ondulin, without stretching the canvases. Twenty nails are required per sheet.