http://www.thisoldhouse.com/toh/skill-builder/0,,211604,00.html it does work.... you just need like 100!!!!!! i just got back from the store and picked up the ice melt... it cant be the rocks tho. and alot of nylons. the cashier at the grocery store, just looked at me kinda funny. dont care. bet this will work tho. we have alot of thick ice on our roof.