The National Roofing Contractors Association conducted limited physical property testing during 2016 on samples of uninstalled asphalt shingles. The goal was to determine whether the samples complied with ASTM D3462, the "Standard Specification for Asphalt Shingles Made from Glass Felt and Surfaced with Mineral Granules." NRCA conducted similar testing in 2001.
This year, NRCA tested eight brands of 3-tab shingles and nine types of multi-layer architectural laminated shingles. Samples came from around the U.S. and represented all U.S. manufacturers.
Only one of the 3-tabs and one of the architectural shingles exceeded the standard's 1,700-gram tear strength requirement. All eight of the 3-tab samples showed granule loss complying with the standard, and all 17 samples passed pull-through and pliability tests.
But tear strength testing results were "notably lower" than those from 2001.
"Some in the industry—including some asphalt shingle manufacturers—may discount this finding because the testing program does not strictly comply with ASTM D3462's product sampling and time of testing requirements," wrote Mark S. Graham, NRCA's vice president of technical services. "However, when comparing the notably lower current test's tear strength values with the 2001 tested values, there appears to be justifiable cause for discussion and additional consideration."