stone coated steel is a scam. yeah you can make big bucks selling and installing it but look around and you will see nothing but failures. i have emails from people all over the country begging for help cause their stone coated roof is failing and the manufacturers and roofers won't return their calls. i tear up for these people. any installer should be able to admit the truth. even as a salesman you dump granules everywhere you go. think about it!