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Squatch Roofing cleared the moss from a brown three-tab asphalt shingle roof in Seattle, WA 98115 with its SasWash roof treatment on August 5, 2026. The July 27 inspection found moss rooted in the shingle seams across the slopes, moss along the flashing of the larger of the home’s two brick chimneys, debris built up on gutters that already had perforated gutter covers, and, on the day of the cleaning, several cracked plastic box vents. The treatment went on the morning of August 5, and the crew’s photos from the next day show the seams clean.
| Location | Seattle, WA 98115 |
|---|---|
| Service | SasWash roof treatment (roof cleaning with gutter clean-out) |
| Property | Single-story home with a long gable roof, two brick chimneys, and a row of box vents along the ridge |
| Inspection | July 27, 2026: attic, roof surface, gutters, chimneys, and vents; 25 photos on file |
| Existing roof | Brown three-tab asphalt shingles; moss in the seams on every slope, moss at the chimney flashing, granule loss in spots, a lifted shingle edge, aged sealant on a pipe boot |
| Also documented | Several plastic box vents with cracked housings (at least three show cracks in the August 5 photos); not part of this job’s scope |
| Gutters | Perforated metal gutter covers in place, with debris built up along them |
| Treatment | SasWash softwash formula applied across every slope, August 5, 2026, following debris removal; follow-up photos August 6 |
| Project investment range | $1,800 to $2,800 |
What Squatch Found on the Inspection
The inspection took place the morning of July 27, 2026 and produced 25 photos. It started in the attic, then moved to the roof surface, the gutters, the two chimneys, and the vents.
- Moss: a line of moss in nearly every seam between the three-tab shingles, on every slope photographed. It was thickest along one seam, where it had built up into a raised line.
- Chimney flashing: moss collected along the counter flashing at the base of the larger brick chimney, with organic buildup on the mortar joints above it.
- Gutters: the gutters carry perforated metal covers, and debris had built up along the covers.
- Shingle surface: granule loss in patches, one small pit in the surface, and a shingle edge that lifted easily by hand at one location.
- Penetrations: a plumbing boot with aged sealant, and box vents holding needle debris under their hoods.
What It Meant and What We Recommended
Why a cleaning, not a replacement
Moss in the seams holds water against the shingle and works under the edges, and on this roof it had been there long enough to build a raised line along one seam. But the shingles under it were still a continuous field. The right call was to remove the growth at the root before it did more damage, not to replace the roof. Squatch quoted the SasWash treatment, which includes the gutter clean-out, and the homeowner approved it.
Why not a pressure wash
Squatch does not pressure wash roofs. Pressure washing strips granules from asphalt shingles, and this roof already showed granule loss in patches. The SasWash process removes the bulk of the moss by hand and then applies a softwash formula at low pressure, which reaches the growth in the seams without stripping the surface.
How the Project Was Completed
The crew set ladders the morning of August 5, 2026. Before the treatment went on, they photographed the roof penetrations: the pipe boots and, one by one, the plastic box vents. Several of the vents had cracked housings, at least three of them with a crack pattern radiating from a hole in the top. Those photos are in the job file. Vent replacement was not part of this job, so the crew documented the condition and moved on.
Squatch’s SasWash process runs in a set order: inspect, blow off large debris, hand-brush the bulk of the moss, apply the softwash formula across the full roof at low pressure, clean out the gutters, and do a final walkthrough. The crew’s photos capture the formula application, with the hose laid across the ridge and the solution wet on the shingles around the chimney and down each slope. The follow-up photos were taken the next morning, August 6, once the surface had dried.
The Finished Result
The August 6 photos show the seams clear across every slope, the shingle surface uniform in color, and the ridge and vents free of the debris that sat under them on July 27. The two photos below are the same ridge line, before and after, shot from the same spot.
What This SasWash Treatment Cost
Project investment range: $1,800 to $2,800. This range reflects the scope of this completed project and is not a current quote. It is anchored on the final invoice total, which includes Washington sales tax.
Roof cleaning is priced by roof area and by how much growth has to come off. This roof is a long single-story gable, so the area is moderate, but the moss was in every seam on every slope, and the gutters carried debris along their covers. A roof with lighter growth would land lower in the range; a two-story roof with the same coverage would land above it.
What Homeowners With Similar Roofs Should Know
Gutter covers do not stop the debris. This roof had perforated covers on the gutters, and the inspection still found debris built up on the covers and in the trough behind them. Roof moss and needles land on top of a cover just as they land in an open gutter.
A roof cleaning is also a roof inspection. The crew that cleaned this roof photographed the vents first and found several cracked housings. That is a repair conversation the homeowner now has photos for, and it came out of a cleaning visit.
Moss in the seams is the early version of a lifted shingle. Moss holds water in the seams and works under the shingle edges, and on this roof one shingle edge already lifted by hand at the inspection. Clearing the growth at this stage costs a fraction of the repair it leads to.
Related questions
How much did this roof cleaning in Seattle cost?
The project investment range for this completed job was $1,800 to $2,800 for a SasWash roof treatment with gutter clean-out on a single-story three-tab shingle roof with moss in every seam. The range reflects this project’s scope and is not a current quote.
Was the roof pressure washed?
No. Squatch does not pressure wash roofs because it strips granules from asphalt shingles. The SasWash process removes the bulk of the moss by hand and then applies a softwash formula at low pressure across the full roof, which the crew photographed going on across the roof on August 5, 2026.
What did the inspection find besides moss?
Moss along the larger chimney’s counter flashing, debris on and under the perforated gutter covers, patches of granule loss, a shingle edge that lifted by hand, and a pipe boot with aged sealant. On the day of the cleaning the crew also photographed several plastic box vents with cracked housings, which were not part of this job.
Were the cracked vents replaced?
Not on this job. The quote and invoice cover the SasWash treatment only. The crew documented each cracked vent with photos on August 5, 2026 so the homeowner has a record of their condition for a follow-up repair.
How long did the cleaning take?
The cleaning was done in one morning visit on August 5, 2026: ladders, the vent and penetration photos, then the formula application across every slope. The crew returned the next morning, August 6, for the follow-up photos once the roof had dried.
Have a roof with similar symptoms?
If moss is lining the seams of your shingles or building up at a chimney, Squatch Roofing can run a free 21-point inspection, show you the photos, and tell you whether a SasWash roof treatment is all it needs. Squatch serves Seattle, the Eastside, and the greater Seattle area. Schedule an inspection or call (425) 292-8327.
This project documentation was prepared by Squatch Roofing from the job records and photos from our crew, September 2026. Technical review by Ben Metsker, Manager, Squatch Roofing.
