An integral roof and gable edge assembly includes a metal or plastic sheet formed with positioning surfaces to facilitate slate tile installation by relatively unskilled roofers. The roof and gable assemblies include one or more hooks for holding one or more slate, ceramic or other similar roofing tiles in fixed position along the eaves and/or gables of a roof. A lift arm can be provided on the roof assemblies to replace cant strips and simplify tile installation. Tiles can be easily installed without nailing through the tiles.