Half Lap Timber Frame Rafters at Ridge3d Isometric, Roof Joinery, Trusses / Leave a Comment / Half Lap, Peg, Rafter 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.