Stronger - 10 times stronger than 30# felt for the ultimate tear resistance * It will not blow off during installation and helps eliminate the need for costly roof repair. * Drier - the unique slip-resistant surface is waterproof to prevent moisture issues. * Lighter - up to 10 times lighter than 30# felt so it"s easy to carry onto a roof. * Faster - the rolls are also 25 percent wider for quicker roof deck coverage.