The covering that places the least load on the structure is the one with the lowest mass per square metre of finished roof surface, not per individual sheet. When choosing, check whether the stated value refers to the covering area and what purlins and additional layers are required. It is also necessary to establish where these loads act and how they reach the walls. A comparison made for the same roof area avoids a misleading impression of lightness. Final design decisions remain with the structural designer.

A multi-pitched roof is a form with several connected slopes, and the choice of covering depends primarily on the geometry and sheet layout rather than on the name alone. Check the detailed drawing of ridges, hips and valleys, along with a cutting plan for the sheets, to assess waste and how details will be formed. For metal roof tiles, T18 or T35, analyse the pitch of each slope, ventilation continuity and drainage. The suitability of a given format should be decided by a full schedule of material and works, left to the designer.

Before choosing a covering, decide whether the cabin will be used only in summer or also in winter — this is the first question before making a decision. The answer affects the layer arrangement, ventilation and the risk of condensation. Check whether a simple T18 or T35 trapezoidal profile suits the structure, and whether a modular metal tile suits a more residential form. Consider rain noise, pitch, batten spacing and site access. Remember that the metal sheet alone does not solve temperature and moisture issues.

A modern roof look is determined by the coherence of the building's form, roof slopes and façade, not by one specific profile or a mandatory black colour. Before ordering material, check how your chosen variant appears when seen from across the street. Deep profiles and broad flashings read differently on a small house, while a delicate texture may disappear on an expansive slope. Compare the sheet layout, the position of laps and cuts, and the availability of accessories. Remember that appearance must be combined with the requirements for pitch, ventilation and structure, and that attic comfort also depends on thermal insulation.

Before ordering a new roof covering, establish what lies beneath the existing one and whether the structure is ready for replacement. This guide sets out how to assess the old substrate, plan the stages of stripping and prepare the area around the building. Check records of earlier repairs, the condition of the roof frame and how moisture is managed, since replacing the visible layer alone does not always solve the problem. You will also learn how to match the support to the sheeting and limit damage during installation. Leave design decisions to the specialist.