Hail damage to asphalt roof shingles

This paper will summarize various tests that the authors have conducted with regard to determining hail damage to asphalt shingles. A specially designed launcher was manufactured to propel ice stones of various sizes and velocities at different asphalt roof shingles. The sizes of ice stones needed to damage the shingles were documented along with the characteristics of such damage. These results were compared to actual hail damage observed in the field. The results of our ten-year study on granule loss also will be presented. In addition, this paper will discuss how to recognize intentional damage to asphalt shingles caused by hammers and other metal objects that are sometimes used to simulate hail damage to an asphalt shingle roof.