The answer to 'asphalt shingles algae growth' is that algae growth on asphalt shingles is a common problem caused by a combination of moisture, shade, and organic debris. Algae can appear as dark, slimy streaks or patches on the roof and can cause the shingles to deteriorate over time. To address this issue, homeowners can try cleaning the roof with a bleach solution or a specialized roof cleaning product, or they may need to replace the affected shingles.
If the algae growth is widespread or the roof is in poor condition, it's best to call a professional roofing contractor to assess the situation and provide a comprehensive solution. Attempting to clean or repair the roof without proper training and equipment can be dangerous and may result in further damage.