Removing algae from a roof
Photo credit: Tim Carter | When cleaning a roof stained by algae, avoid chlorine-based solutions.
1. Check the specs; papers, please
Read any paperwork that came with your shingles concerning their warranty. You want to know how the manufacturer recommends that you clean its product. If you don't have the paperwork, you can frequently get it online at the manufacturer's website.
2. Careful with that pressure washer
Most manufacturers will void the warranty on their shingles...
