Good roof sealants are Leak Stopper, Lanco Ultra Siliconizer and Tropi-Cool, according to the Lowe's, Home Depot and Henry websites. Roof sealants are composed of different materials, such as acrylic or silicone, and different products are designed for use in different climates.
Leak Stopper is a rubberized product that works best for patches, states the Lowe's website. The product is flexible when it dries, which prevents future cracking.
Lanco Ultra Siliconizer is made of 100 percent acrylic silicone, and it is waterproof and durable in extreme weather, says the Home Depot website.
Tropi-Cool is a 100 percent silicone product that is UV resistant, according to the Henry website. The product can be used in a range of temperatures without cracking or hardening.