Roof Cleaning & Moss Removal in Portland, OR
Moss is a fact of life in Portland — but letting it grow unchecked on your roof shortens its lifespan significantly. Our safe soft wash method removes moss and algae without damaging your shingles.
Portland Roofs and the Moss Problem
If you've lived in Portland for a few years, you've probably noticed that green, fuzzy coating spreading across rooftops in your neighborhood. The Pacific Northwest climate — wet winters, mild temperatures, and dense tree canopy — creates near-ideal conditions for moss growth. It's not a question of if your roof will get moss, it's a question of how fast.
Most homeowners assume moss is just a cosmetic issue. It's not. Moss absorbs moisture like a sponge and holds it against your roof surface long after the rain stops. That sustained moisture breaks down asphalt shingles, promotes rot in the wood decking underneath, and creates pathways for water to work under flashing and around seams. Left untreated, a significant moss infestation can shave years — sometimes a decade or more — off a roof's expected lifespan.
We use the soft wash method exclusively for roof cleaning. High-pressure washing removes moss visually but destroys the protective granule layer on asphalt shingles in the process. Our low-pressure, chemical-based approach kills the moss at the root while leaving your roofing material intact. We also offer this service alongside gutter cleaning — since a clean roof means cleaner gutters — and house washing for a complete exterior refresh.
What's Included
- Removes moss, algae, lichen, and black streaks from roofing
- Safe soft wash method — no high-pressure that damages shingles
- Biodegradable cleaning solution kills moss at the root
- Extends roof lifespan by preventing moss-driven moisture damage
- Safe for asphalt shingles, composition, and most roofing types
- Prevents debris buildup that clogs gutters and valleys
Our Roof Cleaning Process
Roof Assessment
We inspect the roof from the ground and on the ladder, identifying moss coverage, algae staining, condition of shingles, and any areas of concern before applying any product.
Protect the Area
Landscaping, downspouts, and the surrounding ground are wetted and protected before we apply any cleaning solution.
Soft Wash Application
We apply a biodegradable cleaning solution at low pressure across the entire roof surface. This product kills moss, algae, and lichen organisms without any scrubbing or high pressure.
Dwell Time
The solution is given adequate time to work into the moss and organic growth. This is where the actual killing happens — we let the chemistry do the work.
Low-Pressure Rinse
A low-pressure rinse removes the loosened material. Dead moss will continue to shed over the following weeks with rainfall, which is normal and expected.
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(503) 412-8449Frequently Asked Questions
Why is there so much moss on Portland roofs?
Portland's climate is almost perfectly suited for moss growth: mild temperatures year-round, heavy rainfall from October through May, and an abundance of shade from the city's tree canopy. North-facing roof slopes and areas shaded by trees are especially vulnerable. Most Portland homes will develop visible moss within 3–5 years without treatment.
Why can't you just pressure wash moss off a roof?
High-pressure washing removes the visible moss but granules on asphalt shingles are blasted off at the same time — those granules are part of what protects the shingle from UV and moisture. Soft washing with a chemical solution kills the moss at the root without damaging the roofing material. It's the method recommended by most roofing manufacturers.
Does moss actually damage a roof?
Yes — over time, significantly. Moss holds moisture against the roof surface, which accelerates the breakdown of shingles and the wood decking beneath them. Moss also works its way under shingles and along seams, creating pathways for water intrusion. Treating moss regularly is significantly cheaper than a premature roof replacement.
How often do Portland roofs need cleaning?
Most Portland roofs benefit from treatment every 2–4 years depending on the amount of shade and tree coverage. After a soft wash, dead moss sheds with normal rainfall. Applying a moss prevention treatment afterward can extend the results. We'll give you our honest assessment when we quote the job.
Related Services
Gutter Cleaning
Moss debris falls into gutters. Clean your gutters the same day as your roof.
Learn more →Soft Washing
The same safe soft wash method used on siding, fences, and other exterior surfaces.
Learn more →House Washing
Get the whole exterior clean — roof, siding, windows, and gutters in one visit.
Learn more →Learn More About Portland Roof Moss
Read our complete guide on why moss grows on Portland roofs, why pressure washing damages shingles, and how soft washing actually works.
How to Remove Moss From Your RoofProtect your roof before the rainy season.
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