Are Gaf Timberline shingles class 3 or 4?

GAF Timberline shingles in their standard form, such as Timberline HDZ and Timberline UHDZ, are neither Class 3 nor Class 4 impact-resistant shingles, they are standard architectural shingles without a UL 2218 impact rating. The Class 3 and Class 4 designations refer to UL 2218 impact resistance testing for hail damage, where Class 4 is the highest rating, providing best protection against hail and often qualifying for insurance premium discounts. Standard GAF Timberline HDZ is tested for 130 mph wind resistance with Dura Grip adhesive and has StainGuard algae protection, but it does not carry a UL 2218 impact rating, so it is considered unrated or Class 0 for impact. If you want GAF Timberline that is Class 3 or Class 4, you need GAF Timberline AS, specifically Timberline AS II, ArmorShield II, which is a Class 4 impact-resistant shingle. Timberline AS II is made with polymer-modified asphalt and a special design that allows it to withstand 2-inch steel ball impacts without cracking. It is rated Class 4 and is recommended for hail-prone areas. So standard Timberline is not Class 3 or 4, but Timberline AS II is Class 4. Always check the product data sheet for UL 2218 rating if impact resistance is important for insurance or weather conditions in your area.