Abstract: A simulated shake shingle for replicating the random appearance of natural wood shakes is provided, the shingle including a generally rectangular top plate having forward and rearward ends, the top plate being rearwardly tapered. A generally rectangular bottom plate is also provided, being secured and partially underlying the top plate and being rearwardly and transversely offset therefrom. The bottom plate is of a size and shape for flush engagement against a flat roof surface and is adapted for side to side engagement with bottom plates of six identical adjoining shingles positioned with the top plates thereof in adjacent nonoverlapping relation. The shingle may also include a plurality of venturi grooves formed on the underside thereof for forming an air insulating barrier to reduce heating or cooling loses from a building interior through the roof.