Roof Pressure Cleaning In MarylandShingle roofs, but also cedar, asbestos, and tile roofs can be washed to remove all staining from tree sap, mold, mildew, pollen, lichen, etc. A special roof cleaner is applied, and then the roof is washed from the top down using a low to medium pressure to remove all visible staining. Our roof cleaning process will clean 100% of all visible stains without causing any damage to the roof. Skilled technicians perform this work with ropes and harnesses in a safe and effective manner. Roofs look great and stay clean for many years.