What is on the GAF Timberline technical data sheet?
Short answer. GAF's Timberline data sheets list each shingle's dimensions, exposure, pieces, bundles and nails per square, plus its test ratings for wind, fire and, where applicable, impact. For Timberline HDZ, GAF lists a 13 1/4 by 39 3/8 inch shingle with a 5 5/8 inch exposure, 64 pieces and 3 bundles per square, 256 nails per square, Class A fire, ASTM D3161 Class F and ASTM D7158 Class H wind ratings, and UL 2218 Class 3 on labeled packages.
Reading the numbers
- Exposure: how much of each shingle shows. A 39 3/8 inch length at 5 5/8 inches of exposure covers about 1.5 square feet per shingle.
- Pieces and nails per square: 64 shingles at four nails each gives 256 nails per 100 square feet. Steep slopes and some warranty terms call for more nails.
- ASTM D3161 Class F: passed a fan-driven wind test at 110 mph.
- ASTM D7158 Class H: the top class of an uplift test, rated for 150 mph design wind.
- Class A fire: the highest fire rating for roof coverings.
- UL 2218 Class 3: survived a 1.75 inch steel ball dropped from 17 feet without cracking, on packages bearing that statement.
When you will need it
HOA submittals: boards often want the product name, color and data sheet. Permits: some Georgia building departments ask for product information. Insurance: insurers that discount impact-rated roofs may want proof of the class. Repairs: the exposure and dimensions help a roofer match a replacement shingle.
Where to get it
GAF posts data sheets and installation instructions in its online document library, and your contractor or supplier can send the current version. Make sure the sheet matches your exact line, since NS, HDZ, UHDZ and AS II carry different ratings. Ratings are lab results, not guarantees, and GAF does not warrant hail performance. See impact-resistant shingles in Georgia, roofing permits in Georgia and HOA roof approval.