Half Lap Timber Frame Rafters at Ridge3d Isometric, Roof Joinery, Trusses This is an exploded view of a pair of 4″ x 9″ timber frame rafters where they meet at the ridge. They are connected with a half-lap joint and peg.The roof pitch is 8/12, and the peg is a 3/4″ x 10″ peg.