The very best sealant out there hands down. This stuff beats silicone all to pieces. I'm a contractor and I've fixed a lot of roofs with a lot of different sealants, none of them holds up like Lexel. When I need to bet on it, this is what I use. It's a little pricier but the stickiness and tough seal cannot be beat. It's a real mess to get off tools and clothes but on the job it never gives up, rots, or turns stiff.