Our non pressure process will not damage your roof shingles since we are able to do everything with garden hose pressure from the safety of a ladder. We will not walk on your roof, and we will not use a pressure washer. While most roof cleaning services utilize a caustic solution, our proprietary cleaning solution is citrus-based, contains algaecide, mildewcide and fungicide and is specially formulated to be gentle on your home and those who share it. A+ Rating from The Better Business Bureau.