Most people think that using a pressure washer is the best way to clean their roof. That is the last thing you want to do! Using a pressure washer to clean your roof can cause multiple issues, such as, loosening the granules on the shingles, causing them to become thin and brittle. Causing them to become thin, will allow water to leak into any small cracks and then you have leaks.
Instead, you can use a water hose with a sprayer a 50-50 combination of standard chlorine bleach. Using bleach helps dissolve mold, algae, moss, and mildew while restoring shingle color. Performing this task will remove wet leaves, twigs, seeds, and other debris that can cause algae, mold, and other contaminants to grow in the first place, extending the life of your roof!