Asphalt shingles have become a widely used roofing material, giving protection and many years of service. These shingles typically come in longitudinal strips having two transverse slots therein forming three rectangular portions which project downwardly from an upper longitudinal body portion. The first step in applying this type of roofing is to cover the roof with roofing felt. The bottom most row of shingles is then nailed into place along the eaves of the roof and along gable ends. Successive rows of shingles are applied from the eaves upward to the ridge of the roof. Building codes for most jurisdictions are very precise as to the spacing and fastening of the shingles to the roof. The most popular dimension for asphalt shingles is a longitudinal dimension having a nominal value of three feet with a tolerance of plus one-eighth inch and minus zero. The building codes which treat this size asphalt shingle state that the shingles must be positioned on centers which are no greater than three feet and one-eighth inch apart with rows having a width in the upward transverse direction of approximately five inches. It takes great skill and stamina to lay asphalt shingles all day in the hot sun and yet to maintain these stringent dimensions. There have been several attempts in the prior art to provide alignment devices for laying asphalt shingles but they generally are cumbersome to operate and are inefficient to use since they must be repositioned after every row of shingles has been laid down.