Seals anything that goes through the roof. Clear brushable sealant. Excellent adhesion to rooftop materials. Elastic and waterproof. This item is not for sale in Catalina Island. Seals Leaks that Asphalt Can't! Ideal for sealing roof leaks, gutters, rooftop fixtures, vents, flashing and more. Lasts 20 times longer than asphalt. Can be applied to wet surfaces and in freezing temperatures. Works in standing water. Excellent UV resistance.