Wind Uplift Model for Asphalt Shingles

Current standard test methods of ASTM and Underwriter's Laboratories for wind resistance of shingles subject a small test deck of shingles, that have been sealed under heated conditions, to a fan-induced airstream impinging at a continuous velocity of 97 km h (60 mph) for 2 h. (ASTM D3161 and UL 997). Although these standard test methods have served a useful purpose in the past, it is generally accepted today that they are deficient in a number of respects. These deficiencies include the test deck not containing any protrusions or valleys, the shingles being sealed under "ideal" conditions, and turbulence of the impinging air stream not being taken into account. In order to improve shingle performance, a wind uplift prediction model was needed. A research program was initiated by ARMA to understand, quantitatively, the uplift mechanism and to develop a prediction methodology suitable for product development. This paper describes the research leading to a quantitative uplift model and presents the results of that research. The investigation included both wind-tunnel and full-scale tests. Uplift forces were found to be significantly lower than forces derived from cladding pressures specified by building codes and standards.