I've tried the roofing crap and although it worked it was the hardest piece of crap to work with. I had to heat it to death with a heat gun before it would get soft enough to stick and even then it was hard to stick. Don't do it. It's hard and its got little rocks in it. Think of really big sand paper. Even though it helped, it didn't help that much and certainly not worth the hard work trying to put it in. Spend the extra money and get a quality product. I'm not going to cheap out any more.