Black streaks and moss removed safely with low-pressure soft washing — no granule damage, no shortened roof life.
Call (571) 463-2680 Get a free quoteThose dark streaks running down Northern Virginia roofs aren't dirt. They're gloeocapsa magma, an algae that feeds on the limestone filler in asphalt shingles. Our humidity and heavy tree canopy give it exactly the damp, shaded conditions it needs, which is why it spreads across whole neighbourhoods.
It will not rinse off in the rain, and it will not stop spreading on its own. Left long enough, the algae holds moisture against the shingles and shortens the life of the roof.
The critical point: a roof must never be pressure washed. High pressure strips the protective granules off asphalt shingles and can void the manufacturer's warranty. We soft wash — low pressure with a cleaning solution that kills the organism at the root, so the streaks don't simply grow back next season.
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