Short Answer
Impact-resistant shingles are products designed and tested to provide increased resistance to impact under specified testing standards. The homeowner should review the actual product classification rather than relying on the phrase 'impact resistant.'
Detailed Explanation
Impact-resistant shingles are tested against a standard (typically ASTM D3161 or UL 2218) that involves dropping a steel ball onto the shingle from a specified height and measuring whether the shingle cracks or tears. Shingles that pass receive a classification (Class 1 through Class 4, with Class 4 being the highest). The classification indicates how the shingle performed under test conditions — not a guarantee against all hail damage. Some insurance companies offer premium discounts for impact-resistant roofs, but homeowners should verify the specific classification and check with their insurance carrier about potential discounts.
Why It Matters
Impact-resistant shingles can reduce hail damage risk and may qualify for insurance discounts, but 'impact resistant' doesn't mean 'hail-proof.'