Abstract: An apparatus for applying roofing shingles includes a tracking assembly having a guide track supported by rails removably coupled to the roof and incrementally adjustable upwardly of the roof by increments corresponding to the desired overlap of successive courses of shingles to be laid on the roof. A carriage movably engages the guide track and supports a supply of shingles on edge, which shingles can be laid upon the roof by individually rotating a shingle forwardly causing it to fall from the platform into a positioning cradle of the carriage. A nailing gun is periodically actuated to secure each shingle to the roof as the carriage moves along the track in preparation for installing the next adjacent shingle.