Shingles have a granulated surface which collects organic byproducts from trees and plants. This surface, when combined with sunlight or indirect sunlight and moisture, is ideal for moss, algae, lichen and fungi growth. Moss and lichen for example, actually grow into the shingle and take root between granules. This process not only discolors the shingle, but damages the shingle by weakening granule adhesion the way tree roots can break up concrete or asphalt. In addition, metal pipe boots, metal vents, flashing, or other metal products may create rust stains on your roof system.
CLEANING GUTTER SYSTEMS:
Because aluminum oxidizes and aluminum gutters are sealed with a porous finish coating, permanent staining by organic material is inevitable. Usually staining is caused by leakage and water pollutants and is accelerated by systems that are not maintained properly. Pressure washing techniques will significantly improve the appearance of your gutters.
CLEANING VINYL SIDING:
Trees and other plants produce sap that becomes airborne and sticks to siding. Sap, containing sugar, is a food source for mold and algae. Rain residue will collect dirt and dust and promote mildew growth. Not unlike the porous exterior finish of gutters, siding can stain and even discolor during long-term exposure to the sun. While cleaning your siding will significantly improve its appearance.