Viking Shield is 25 times stronger and more durable than the leading 15-pound felt. Its superior lay-flat properties and water resistance keep it from warping, winkling, and cracking in cold weather, while its enhanced UV protection reduces heat buildup on hot days. It's also 100% inorganic, so it will not rot or mold. With less weight per roll, Viking Shield is easier to handle during all stages of installation, while remaining strong enough to resist tearing and stretching in high-traffic areas and during high winds. Viking Barriers' proprietary SlipGuard skid-resistant surface offers dynamic steep-slope traction, ensuring the best walking surface available. Plus, Viking Shield is environmentally responsible and may contribute to your LEED and RGBP ratings.