Disclosed herein is an assembly that relates to a roof assembly comprising, at least one first waterproof membrane for covering a building roof and a stiff member sealed within at least one second waterproof membrane. The stiff member being substantially aligned with a perimeter of the building roof, and the first waterproof membrane being sealedly attached to the second waterproof membrane. The stiff member being attached to a structure of the building by a plurality of fasteners.