A CORRECTLY installed EPDM roof goes OVER the sides and down about 1 inch. NO OEM I am aware of(I have replaced hundreds of EPDM roofs) ever stops at the edge. The rubber goes underneath the front cap from the factory and over the top and down the sides and backwall about 1 inch. Usually the overlap is about 6 to 8 inches and after the top trim and awning rail is installed, they trim the EPDM even with the bottom of those side rails. That gives you that 1 to 1.5 inch overlap. Even the old Aluminum roofs overlapped. Doug