Those black streaks and green moss patches on Rapid City roofs are living algae and moss that hold moisture against your shingles and shorten roof life. Soft washing clears them safely at low pressure. Here is what roof cleaning costs in the Rapid City area and why soft washing is the right method.
Roof soft washing in the Rapid City area typically runs about $300 to $700. What sets the price:
We quote flat by the job. Request a quote and tell us the approximate roof size and how many stories.
A pressure washer will blast the protective granules right off asphalt shingles, void many manufacturer warranties, and shorten the life of the roof. Soft washing is the method roofing manufacturers actually recommend: low pressure plus a cleaning solution that kills the algae and moss at the root so the roof stays clean far longer than a rinse alone. The same gentle approach protects your siding, which is why house and roof are so often cleaned together.
The black streaks are Gloeocapsa magma algae feeding on shingle filler, and under Rapid City's pine cover, moss takes hold on shaded, north-facing slopes where it stays damp. Both trap moisture against the roof, lift shingle edges, and accelerate wear — a real concern with the freeze-thaw swings here. Clearing them protects the roof and instantly brightens the whole house. Many homeowners add gutter brightening while we are up there.
Usually $300 to $700 depending on size, pitch, stories, and how much algae and moss are present.
No — soft washing uses low pressure and cleaning solutions; it is the roofing-recommended method and protects your warranty.
They are algae feeding on the shingle filler; soft washing kills it at the root so it does not come right back.
Because soft washing kills the growth rather than just rinsing it, results typically last far longer than a pressure-only clean.
Visit the full FAQ page for more.
Soft wash siding to match your clean roof.
Clear black stripes from gutter faces.
Bring back stained driveways and walks.
You can also review deck & fence cleaning, commercial pressure washing, and the areas we serve.