A tile assembly having a plurality of tiles adapted to join in an interlocking and repeating fashion. A plurality of tile assemblies can be joined to each other to form a roof. Each tile assembly includes left and right center tiles positioned side-by-side. Each tile has a generally diamond shaped main surface with vertically spaced upper and lower apices and laterally spaced lateral apices. Two upper flanges extend upwardly and outwardly from the main surface along upper edges and are joined in an upper flange apex. Each center tile includes two lower flanges that extend downwardly and outwardly from the main surface along the lower edges. The tile assembly includes upper and lower tiles of the same configuration. The upper tile fits over the adjacent upper flanges of the two center tiles, and the lower tile fits beneath the adjacent lower flange of the two center tiles.