Roof Cleaning and Black Streak Removal on Long Island
Those black streaks are algae eating your shingles. We take them off without taking the granules with them.
Soft wash roof cleaning for asphalt shingle, cedar shake and flat roofs across Long Island. No high pressure, no walking damage, no voided warranty.
The black streaks on Long Island roofs are gloeocapsa magma, a hardy algae that feeds on the limestone filler in asphalt shingles. JV Power Washing removes it using a low-pressure soft wash that kills the algae at the root without dislodging the shingle's protective granules. High-pressure washing a shingle roof strips those granules and shortens the roof's life.
What happens when this surface is left on Long Island.
Those black streaks on your roof are not dirt. They are gloeocapsa magma — a blue-green algae that feeds on the limestone filler inside asphalt shingles. It spreads fastest on damp, shaded, north-facing roof sections. As it grows, it holds moisture against the shingle, which accelerates decay, lifts edges, and shortens the roof's life. Moss is worse — its roots physically pry into the shingle surface. Pressure washing a roof to remove any of this strips the protective granules off the shingle, voids most manufacturer warranties, and makes the problem return faster. The only safe method is a low-pressure soft wash that kills the organism at the root.
Those black streaks are algae eating your shingles. We take them off without taking the granules with them.
Scroll to watch the black algae dissolve from ridge to eave — without a single granule stripped.
What is happening on your shingles
Years of roof life lost to untreated algae
Algae holds moisture against the shingle, accelerating decay. Soft washing stops the damage before it shortens your roof's life.
The roof cleaning process, step by step.
Assess the roof and growth type
We identify whether the streaks are algae, moss, or lichen, and the roof material — asphalt shingle, cedar shake, or flat. The solution is mixed accordingly.
Protect property and landscaping
Downspouts are managed, landscaping is pre-wetted, and runoff is controlled to keep solution off plants.
Apply soft wash solution from ladders and ground
A roof-specific solution is applied at low pressure — under 100 PSI — from ladders and the ground wherever possible, to avoid foot traffic on shingles. It is left to dwell and kill the algae at the root.
Gentle rinse and moss removal
Dead algae is rinsed away at low pressure. Moss is treated, killed, and removed without scraping or pressure that would damage the shingle surface.
Drag to see the difference.
Every photo is a real JV Power Washing job on a real Long Island property.
AfterBeforeSayville — Roof and siding combo — full refresh
AfterBeforeBrookhaven — Roof-to-foundation clean
AfterBeforeMastic — Coastal roof — algae treated
Clear pricing. No surprises.
From $399 for a standard residential roof.
Reviewers repeatedly call our pricing "extremely reasonable" and "the best price I found around." We publish starting prices because hiding them helps no one.
What moves the price:
- Roof size and pitch
- Roof material (asphalt shingle, cedar, flat)
- Severity of algae, moss and lichen growth
Every quote is written and agreed before we start. The price you see is the price you pay.
Why homeowners trust us with this.
Twenty five years on Long Island. The same crew every visit. The reviews to prove it.
The JV Clean Promise
If you are not completely happy with the result, we will return and re-clean the area at no extra cost. You only pay when the job is done right.
What real customers say about this.
"Eight years and counting. Every season they bring the property back to life. Punctual, professional, and the work speaks for itself."
Michael Donahue
8 year customer
"House and fence look brand new again. The crew was careful with the landscaping and left everything spotless."
Susan Hunter
Verified customer
"Professional and friendly from start to finish. Everything looks clean and fresh afterwards."
Chris Marshall
Verified customer
Related services
Serving 19 towns across Long Island
Roof Cleaning — your questions, answered.
Those black streaks are algae eating your shingles. We take them off without taking the granules with them.
Free on-site assessment. Clear written quote. The JV Clean Promise.