Abstract: A flat roof cover system comprising a facia edge plate and a generally flat roof substructure which includes a nailable perimetral edge strip, and a waterproof rubber-like membrane cover of a length to extend beyond the edge strip. A rigid clip having a flat nailing portion is nailed to the upper face of the edge strip. The clip has a rigid inversely disposed V-shaped portion with a wall extending down along the building which terminates in a lock flange. A facia plate, having a like deformable resilient V-shaped portion terminating in a reversely turned edge bearing on said membrane edge and the clip plate gravel stop surface beneath it, has a latch socket to snap over said lock flange.