Before selecting a new covering, settle which roof layers are to stay and which will need rebuilding. That decision governs how much stripping is required, whether battens and membrane must be renewed, and the fixing method for the sheeting. Examine the timber, the joints and the bearing points, along with any earlier modifications and the insulation planned. Bear in mind that a lightweight material cannot compensate for a weak truss. The programme of works ought to cover weather protection for the building and the order in which deliveries arrive. Only once these matters are resolved should a sheet profile be chosen to suit the slope geometry and the existing structure.

The choice between modular metal tile and trapezoidal sheeting depends mainly on the roof geometry and the desired pattern of lines across the slope. Metal tile mimics the fine rhythm of small roof elements, while trapezoidal profile creates pronounced longitudinal ribs. Before comparing costs, check whether a given profile suits the pitch, the support spacing and the number of valleys and dormers. Also consider the effective cover width and how sheets are cut, as these affect waste. Only then compare coatings, insulation and acoustics.

The type of roof covering should be chosen above all to suit the roof pitch, the building structure and the function of the rooms beneath the roof, not merely the appearance of the surface. It is therefore worth first establishing whether an overlapping covering or a continuous waterproof layer is needed, and distinguishing a thin sheet of metal from a sandwich panel or PIR insulation. Check what pitch and support the system requires and whether the chosen material is permitted in that particular assembly.

Tile-effect metal roofing, T18 and T35 can be used on house roofs if they suit the design and installation conditions. They differ in appearance, geometry and method of cutting. A higher profile alone does not mean a better roof. The choice should be determined by roof pitch, support, full cost and aesthetic expectations. The comfort of the attic, however, depends on the entire layer system, not just the shape of the outer sheet. Tile-effect metal roofing has transverse ribs that divide the surface into rows resembling roof tiles. Trapezoidal steel sheet forms a simpler pattern of long, parallel ribs. T18 gives a finer pattern than T35. The profile height affects the shadow, so the same colour may look different on each of these coverings.

The protective layer on steel roof sheeting limits the environment's impact on the steel core, but it does not replace the required amount of steel. When choosing a covering, two decisions must therefore be kept separate: the profile and its resulting geometry, and the protection system on both sides of the sheet. It is worth checking which metallic and organic coatings are used, how their mass is declared, and whether the underside protection suits the building's conditions. Colour or coating name alone does not determine durability – continuity of the surface and how the roof is used are what count.