Algae growth staining entire roof planes black
Why it happens here
The humidity off the lakes keeps roof surfaces damp longer than inland areas, and that is exactly what algae needs to spread. It shows up first on the north-facing slopes that stay shaded and wet the longest.
Our approach
We install algae-resistant shingles on replacements and treat existing roofs with a cleaning solution that kills the algae without damaging the shingles. On maintenance visits, we check the north slopes first because that is where it starts.