Do impact-resistant shingles work?
How they are designed to work
A standard shingle fails under hail when the impact fractures the mat or knocks granules loose. Impact-resistant shingles either flex instead of fracturing, using rubberized SBS modified asphalt, or spread the blow with a heavier mat or polymer backing. The result is fewer cracked mats and fewer bruises that turn into leaks later.
What the lab test shows, and what it does not
UL 2218 drops steel balls on a shingle under controlled conditions; Class 4 survives a 2-inch ball dropped twice from 20 feet. Real hail is different: stones vary in density and shape, wind drives them in at angles, cold shingles are stiffer, and storms repeat over the years. The rating is a useful comparison between products, not a guarantee for a specific storm.
Where they still fail
- Hail near or above 2 inches, especially when driven by strong wind.
- Older roofs, as sun exposure gradually stiffens the asphalt.
- Poor installation, which no rating can make up for.
- Cosmetic marks, which can appear even when the shingle still works.
What it means for you
In a typical Georgia spring storm with 1 to 1.5 inch hail, a Class 4 roof is more likely to come through with no functional damage, saving you a deductible and a disruptive reroof. Shingle warranties exclude hail regardless of rating, and some policies treat cosmetic and functional damage differently, so know your policy. Read more in impact-resistant shingles in Georgia and Georgia hail season.