Loudoun’s 1990s-and-newer subdivisions are hitting the age where black streaks (Gloeocapsa magma algae) show on every north-facing slope. Shingle manufacturers specify one safe removal method — and it isn’t a pressure washer.
Our method
Soft-wash application at rooftop chemical strength, dwell time to kill growth at the root, then a no-pressure rinse. Gutters get flushed after. HOA-visible results without a single granule stripped.
What to expect
Streaks disappear on treatment day; heavier lichen releases over the following rain cycles — we tell you that up front.
Images are illustrative — project photography from our completed jobs is being added. Every method described here is exactly how our crews work.