Building element with varying surface characteristics

A building element is formed from sheet material having opposite major surfaces that extend between longitudinal edges. Margins of the sheet adjacent the longitudinal edges are turned out of a mid-plane of the sheet to form opposite profiled sections ( and ). The major surfaces of the building element have different surface characteristics, and one profiled section has one of the major surfaces as its outer surface, and the other profiled section has the other major surface as its outer surface.