Profiled metal sheeting has been used for domestic roofs and, more commonly, in commercial and industrial buildings for many years. As with other thermally responsive construction, when elements having a high resistance to water vapour are incorporated there is a potential risk of condensation, which can be increased if thicker insulation is used. Condensation can reduce the thermal performance of the roof and cause disruption to internal finishes. This Good Building Guide highlights typical profiled metal roof constructions, some of the technical risks associated with increased levels of insulation and the design aspects which should be considered. 6 pages.