Roof cleaning is the process to remove dirt, algae and moss from roofs. Roof cleaning can extend the duration of a roof’s ability to function. Algae and other types of build-up often form on parts of roofs that are shaded, and can reduce a roof’s life expectancy. The presence of soot, dirt, or biomass can affect how much sunlight is absorbed by a roof and thus the amount of heat a building absorbs. Cleaning may be accomplished with a bleach or vinegar solution, various cleaning products or commercial cleaning services. The addition of zinc strips near the roof’s peak may reduce the regrowth of algae and moss.