Begin by establishing whether the old sheets actually contain asbestos, rather than judging them by colour and shape. If documents are missing, agree the identification method with the relevant authority and a contractor; do not take samples by breaking or drilling yourself. At the same time, assess the condition of the roof structure and the geometry of the slopes, since some problems only become visible once the sheets are removed. The choice of new covering — trapezoidal sheet or metal tile — depends on pitch, structure and building function. Also plan the safe removal of the old material and check with the municipality whether asbestos support covers only dismantling, transport and disposal.

Choose the covering to suit the roof pitch, the building structure and the way the building is used. Tile-effect metal roofing, trapezoidal steel sheet and insulated sandwich panels serve different functions. What matters is the cost of the whole roof build-up, as well as appearance, acoustics and the possibility of repair. Colour or the price of a single sheet is not enough. First check the design requirements, then compare the solutions approved for the given roof slope. Start with the pitch and dimensions of the slope. Every product has its own range of application. Tile-effect metal roofings come with different minimum pitches, so the parameter of one model does not apply to the whole group. At a low pitch, the laps, flashings and the method of water drainage become particularly important. The product data sheet and the installation instructions must be consistent with the design.