Unlike membrane roof systems, which are designed for wind uplift based on uplift-resistance pressures, asphalt shingle roof systems are classified based on wind speeds. Following is a brief overview of the wind-resistance methodologies applicable to asphalt shingle roof systems.
ASTM D3161, "Standard Test Method for Wind-Resistance of Asphalt Shingles (Fan-Induced Method)," evaluates the wind resistances of discontinuous, air-permeable, steep-slope roofing products, including asphalt shingles, by delivering a stream of air across test deck specimens. A minimum of two test specimens are subjected to test velocities of 60-, 90- or 110-mph winds for two hours. During the tests, the test specimens are observed for any damage, including disengagement of a sealed tab. Test specimens exhibiting damage are considered to have failed the test.
Asphalt shingle test specimens passing the two-hour test duration at 60 mph are classified as Class A; those passing at 90 mph are classified as Class D; and those passing at 110 mph are classified as Class F.