If you choose metal-tile sheet

Metal tile roofs

If you choose metal-tile sheet for your house roof covering you have to note the following details. 
While ordering please check metal-tile sheet length and so called working width; The length of metal-tile is defined according to the step (eg. 300mm). The length of the sheet should match the inclination length. In spite of lightness of the metal-tile the length can't be infinite. The edges of the metal-tile sheets are cut according to the step sizes (while covering, if the sheet is being cut in the place it is important to foresee step wave completeness for visual beauty and perfection).
roof boarding should match metal-tile step size, for example if metal-tile step is 30 cm, roof boarding should be done at each 30 cm;
Next step: drainage system should be fixed on the roof; after drainage system the roof is insulated, which can be of different types. 
The best thermal insulation is foiled faced glass-wool, for soundproofing is also used penoplast...
Next step - fixing roof sheets.  Should be fixed with screw. The screw should be fixed with 90 degree towards the roof flat area.
Last stage is fixing pitch breaks.