San Diego Roof Soft Washing Service
Dark streaks, black stains, and green patches on roofs in San Diego are almost always caused by algae (Gloeocapsa magma), moss, or lichen — not dirt. These organisms feed on limestone filler in asphalt shingles, gradually degrading them and shortening roof life. Soft washing — low-pressure cleaning combined with specialized biocidal solutions — kills these organisms at the root and restores the roof's appearance without the granule loss and shingle damage caused by high-pressure washing.
Roof soft washing in San Diego costs $250–$450 for a 1,500 sq ft roof and $350–$600 for a 2,500 sq ft roof. 32 of 32 verified providers in San Diego offer roof soft washing as a standalone service or bundled with house exterior cleaning. Service covers the San Diego metro area including San Diego County, La Jolla, Encinitas. Never allow any provider to pressure wash an asphalt shingle roof — the Asphalt Roofing Manufacturers Association (ARMA) explicitly recommends against it. Only soft wash is appropriate.
After soft washing, treated algae and moss may not disappear immediately — biological material dies and washes away gradually over the next few weeks of rain. This is normal and expected. The roof will continue to lighten for 4–8 weeks following treatment. A second visit is rarely needed. Many San Diego homeowners schedule roof soft washing every 3–5 years or as soon as dark streaks reappear.
San Diego Providers Offering Roof soft washing
gutter cleaning · window cleaning · drone documentation
window cleaning · graffiti removal · junk removal · salt buildup removal · paint preparation +1 more
sealing · pigeon proofing · water spot removal · fire damage restoration
gutter cleaning · roof cleaning · oil stain removal · graffiti removal · mold and mildew removal
rust stain removal · mold and algae removal · preparation for painting or sale
gutter cleaning · screen cleaning and repair · stainless steel cleaning · water reclamation
graffiti removal · rust removal · oil stain removal
gutter cleaning · window cleaning · parking lot sweeping · day porter service · trash removal +2 more
gutter cleaning · gutter brightening · window cleaning · rust removal · stain removal +2 more
gutter cleaning · window cleaning · solar panel cleaning
mold and mildew removal · algae removal · oil stain removal
gutter cleaning · stubborn stain removal · rust treatment · oil stain removal · grease cleanup +1 more
window cleaning · gutter cleaning · solar panel cleaning · turf cleaning
window cleaning · sealing/staining after wash · outdoor furniture cleaning
window cleaning · gum removal · oil removal · algae/mold/mildew removal and prevention · bird dropping removal +5 more
water recovery · gutter cleaning (implied) · window cleaning (implied) · carpet cleaning · tile and grout cleaning +5 more
gutter cleaning · window cleaning · tile & grout cleaning · re-sealing · solar panel cleaning +1 more
gutter cleaning · solar panel cleaning · skylight cleaning · window tinting
window cleaning · gutter cleaning (implied by eave cleaning)
gutter cleaning · concrete staining · concrete sealing · epoxy coatings · sandblasting +1 more
gutter cleaning · window cleaning · screen cleaning
gutter cleaning · window cleaning · paver cleaning & sealing · solar panel cleaning · skylight cleaning +5 more
gutter cleaning · solar panel cleaning · skylight cleaning · mirror cleaning · light fixture cleaning +5 more
gutter cleaning · downspout flushing · system inspection · preventive maintenance · deck staining +5 more
window washing
gutter cleaning · window cleaning · deck painting · deck sanding · deck sealing +5 more
gutter cleaning · window cleaning · solar panel cleaning · home care plan · window care plan +1 more
gutter cleaning · window cleaning · solar panel cleaning · dryer vent cleaning
Roof Soft Washing FAQ — San Diego
How much does roof soft washing cost in San Diego?
Roof soft washing in San Diego costs $250–$450 for a 1,500 sq ft roof and $350–$600 for a 2,500 sq ft roof. Larger or steeper roofs run higher. Bundling with house exterior washing usually saves $50–$100. Compare quotes from 32 providers in San Diego for your specific roof size and pitch.
Is pressure washing safe for my roof in San Diego?
No — high-pressure washing on asphalt shingles strips protective granules, voids manufacturer warranties, and can force water under shingles causing leaks. The Asphalt Roofing Manufacturers Association (ARMA) recommends against pressure washing shingle roofs. Soft washing is the only appropriate method. If a San Diego company recommends pressure washing your shingle roof, it's a significant red flag.
What causes dark streaks on my roof in San Diego?
Dark streaks on San Diego roofs are almost always caused by Gloeocapsa magma — a blue-green algae that feeds on the limestone filler in asphalt shingles. Green patches are typically moss. Black or dark areas with texture are often lichen. All three are killed by soft washing solutions. Left untreated, they can significantly reduce shingle lifespan by degrading the granule layer.
How often should I have my roof soft washed in San Diego?
Most San Diego roofs benefit from soft washing every 3–5 years, or sooner if significant algae streaking appears. Homes in shaded, humid, or heavily treed areas may need cleaning every 2–3 years. After soft washing, results typically last 2–4 years before biological growth visibly returns. Some San Diego companies apply preventive zinc or copper strips after washing to slow regrowth.