Roof Rejuvenate replaces oil that has dried out with all-natural oil to allow for expansion & contraction. A Roof Rejuvenate Treatment Extends Life by Restoring Flexibility and Waterproofing Protection Daily expansion and contraction is critical to your roof's performance and longevity. As a roof ages, oil dries out, causing asphalt roof shingles to become brittle. This slowly breaks the roof apart, similar to the way a pothole develops in the road. Roof Maxx is a powerful, scientifically formulated, all-natural treatment, derived from soybean oil (soy methyl ester). Soy-Fusion Technology allows millions of micro beads of oil to quickly penetrate brittle asphalt roof shingles. This rejuvenates the asphalt, restoring flexibility, facilitating daily expansion and contraction. Treatment with Roof Maxx is 100% safe for people, pets, property, and the environment. Work is completed in about an hour, with zero mess, for just a fraction of the cost of a new roof.