To clean moss stains from an asphalt shingle roof, use a brush to scrape the moss off of the shingles, and then spray the roof with a mixture of half water and half bleach. Avoid using a pressure washer to apply the mixture as the high pressure can damage the shingles.Continue Reading
To clean moss or algae from shingles:
Use a brush to scrape the moss or algae off the asphalt shingles.
Create a cleaning mixture of half water and half bleach and pour over the shingles.
To prevent future moss or algae growth, install zinc or copper strips underneath the shingles at the top of the peak of the roof. The metal strips allow rainwater to wash some metal molecules over the shingles, which prevents future algae and moss growth.