The answer to 'underlayment algae growth' is that algae growth on roofing underlayment is a common problem that can be caused by moisture, poor ventilation, and exposure to sunlight. Symptoms include unsightly green or black staining on the underlayment, which can eventually lead to premature deterioration of the roofing materials. To address this issue, homeowners should first ensure proper roof ventilation, clean the affected areas, and consider applying an algaecide or fungicide solution. In some cases, replacing the underlayment may be necessary if the growth is extensive.
If the problem persists or the homeowner is unsure of the best course of action, it's recommended to consult with a professional roofing contractor. They can properly diagnose the issue, recommend the appropriate treatment, and ensure the roof is functioning as intended to prevent future algae growth.