US Patent 8474220 Premanufactured roof plate element

A prefabricated roof plate element (4), including one or more longitudinal box-shaped girders (24), each having two predominantly U-shaped metal sections (10, 18) which at mutually facing, open sides are interconnected along narrow outwards bent lateral edges (5). The girders (24) are connected at upper and lower sides (19) corrugated in longitudinal direction which office corrugated metal plates (7) which are corrugated in a transverse direction and have approximately the same width as the roof plate element (4). The girders (24) are disposed along opposed sides and at a center of the roof plate element (4). One of the sections (10, 18) is shorter than another one of the sections to forming eaves (6).