Dark streaking on a roof is typically caused by algae (often gloeocapsa magma), while moss tends to grow on shaded, moisture-retaining sections of the roof -- both common issues on Des Moines homes with mature tree cover. This service targets the specific growth with treatment suited to the type present.

  • Addresses dark algae streaking specifically
  • Moss removal from shaded or moisture-retaining roof sections
  • Treatment suited to the specific growth type present

Common Algae & Moss Removal situations in Des Moines

Dark streaks or discoloration on north-facing or shaded roof areas

This is the classic pattern for Gloeocapsa magma algae growth — shaded areas retain moisture longer, giving algae more time to establish.

Visible moss growth, especially in valleys or shaded roof sections

Moss holds moisture against the shingle surface, which can accelerate granule loss and shorten roof life beyond what algae alone would cause.

A roof that hasn't been cleaned in 2+ years

Professional soft wash treatment typically keeps a roof clean for two to five years — a roof well past that window is due for a treatment before streaking becomes more visually and structurally significant.

Algae & Moss Removal FAQs

What's the safest way to clean black streaks off asphalt shingles?

The dark streaks on many Des Moines roofs are usually algae, not dirt. The Asphalt Roofing Manufacturers Association's guidance is to apply a diluted chlorine bleach solution at low pressure and let it work, rather than scrubbing or pressure washing, which can strip the protective granules from shingles. Professional soft washing follows the same principle with controlled mixes, and protects plants and gutters with pre-wetting and rinsing. Check your shingle warranty, too: some manufacturers specify approved cleaning methods.

This content is reviewed by the Des Moines Roof Cleaning editorial team and informed by licensed-contractor sourcing, manufacturer documentation, and established industry standards for Roof Cleaning. Read our editorial standards.