Walk down Delaware Avenue or Kenwood Avenue and look up: many of Delmar's roofs carry dark streaking on the north slope, especially on the Colonials and Capes tucked under the town's signature mature street trees. That's gloeocapsa magma, an algae that feeds on the limestone filler in asphalt shingles and thrives wherever roofs stay damp.
Delmar's proximity to the Hudson bluffs near Glenmont and Normansville adds extra humidity to the mix, while the heavy tree cover throughout Slingerlands and Elsmere blocks the sun that would otherwise dry shingles out quickly after rain. Older homes with north-facing dormers and gables are especially prone to the buildup.
High pressure strips the streaks temporarily but also strips shingle granules and can void your roof's warranty. Our soft-wash treatment uses ARMA-approved solutions applied from the ground or ladder to kill the algae at the root — restoring the clean rooflines that match Delmar's well-kept streets.