Roof Cleaning & Moss Removal in Snohomish County, WA
Moss is the number one roof killer in the Pacific Northwest. We remove it without wrecking the shingles.
Western Washington gives moss everything it needs: shade, moisture, and mild winters. Left alone, it lifts shingle edges, holds water against the roof surface, and works its way under the courses until the deck below starts to rot. It is the single most common reason PNW roofs fail early.
We remove moss the way manufacturers actually approve — manual removal and treatment, never a pressure washer. High-pressure water blasts away the protective granule layer and can take a decade off an asphalt roof in a single afternoon.
What's included
We use low-pressure washing on roofs 10 years old or newer. Older or fragile roofs get soft manual cleaning to protect granules and warranties.
Moss and debris removed by hand and with soft tools so the shingle surface stays intact.
Roof-safe moss treatment that kills remaining spores and slows regrowth.
Debris pulled out of gutters and valleys so water actually drains where it should.
While we're up there we flag any lifted, cracked, or missing shingles we find.
When to call us
- Green or black clumps along shingle edges and in valleys
- Dark streaking across north-facing slopes
- Gutters filling with granules and organic debris
- Heavy tree cover shading the roof most of the day
- It's been 2+ years since the last cleaning
- Shingle edges visibly lifting where moss has grown under them
How it works
- 1. Assessment
We check moss coverage, shingle condition, and whether the roof is safe to walk.
- 2. Debris removal
Needles, leaves, and branch litter cleared from the field, valleys, and gutters.
- 3. Manual moss removal
Growth removed by hand without disturbing the granule surface.
- 4. Treatment
Roof-safe product applied to kill residual growth and slow the comeback.
What it costs
Most residential roof cleaning and moss removal projects fall between $500 and $1,500 depending on roof size, pitch, and how established the growth is. Recurring moss treatment is included on our Complete and Premier maintenance plans.
Frequently asked questions
Why not just pressure wash it?
Pressure washing removes the ceramic granules that protect asphalt shingles from UV. It looks clean for a season and costs you years of roof life — and it typically voids the manufacturer warranty.
How often does moss come back?
In shaded Snohomish County yards, expect noticeable regrowth in 2–4 years without treatment. Annual maintenance and regular treatments stretch that out considerably.
Can you clean a metal roof?
Yes, and metal is far less hospitable to moss in the first place. Cleaning is mostly debris removal and a rinse.
Will cleaning fix my leak?
Cleaning removes the cause of future damage but doesn't repair existing damage. If we find a leak source while cleaning, we'll show you photos and quote the repair.
Where we provide this service
Ready when you are
Free estimates across Snohomish and King County. Call (425) 900-4828 or request yours online — most homeowners hear back the same day.