Painting a sheet-metal roof makes sense only when the metal is sound and the old coatings and causes of damage have been identified. This guide gives owners and contractors the criteria for judging whether a covering is suitable for renovation and the steps needed to prepare it. It is worth checking the degree of corrosion, coating adhesion and the condition of fixings, as well as the underside of the sheets, where rust will not disappear after painting. Removing the source of recurring damage before new paint protects the prepared substrate is equally decisive.

Metal sheeting suits an energy-efficient house only as part of a complete, well-considered roof assembly, not as a stand-alone solution. Before approving the design, it is worth checking the continuity of insulation, air tightness and how the eaves, ridge and service penetrations are detailed. Equally important are the declared lambda of the insulating material and the choice of counter-batten fixings capable of carrying the covering loads. Whether the roof meets its targets depends on how all layers work together with the rest of the building, so the thermal assessment should cover the whole assembly rather than a single sheet.