What are Class 3 impact resistant shingles?
Short answer. Class 3 shingles have passed the UL 2218 test with a 1 3/4 inch steel ball dropped from 17 feet, striking the same spot twice without the shingle cracking. They resist hail better than unrated shingles, but most insurance discounts and storm programs only recognize Class 4, the top rating.
Where Class 3 sits on the scale
- Class 1: 1 1/4 inch ball from 12 feet.
- Class 2: 1 1/2 inch ball from 15 feet.
- Class 3: 1 3/4 inch ball from 17 feet.
- Class 4: 2 inch ball from 20 feet.
A shingle passes a class when the test leaves no cracks or ruptures visible on the shingle.
You may already have it
Class 3 is often a byproduct of a well-built standard architectural shingle rather than a separate premium product. GAF, for example, lists its standard Timberline HDZ as Class 3. That means a roof can carry a Class 3 rating without the homeowner ever having asked for impact resistance.
Class 3 versus Class 4 in practice
- Insurance: carriers that offer impact credits almost always require Class 4, so Class 3 rarely changes your premium. Ask your agent.
- Construction: Class 4 shingles usually add rubberized SBS asphalt or a reinforced mat. Class 3 shingles are typically conventional shingles that tested well.
- Real hail: lab steel balls and real ice behave differently. Both ratings improve your odds against common hail sizes, and neither makes a roof hail proof.
Is it worth paying extra for Class 3?
Generally no. If impact resistance is your goal, compare a standard architectural shingle with a true Class 4 option. If the Class 3 rating comes with a shingle you already like at no added cost, it is a pleasant bonus.
See impact resistant shingles in Georgia and Georgia hail season.