Home › Recent Projects › SasWash Roof Treatment in Snohomish, WA (Mossy Box Vents, Small Tune-Up)
Squatch Roofing treated the laminate shingle roof on a two-story home in Snohomish, WA 98290 with its SasWash roof treatment on October 27, 2026, and did a small tune-up in the same visit. The October 13 inspection found moss growing in the shingle joints and thick moss and lichen on the plastic box vents. Before the wash, the crew sealed the fasteners on the vent and pipe flanges and dabbed sealant over exposed nail heads; after it, they sealed the vent flange corners and a wall flashing.
| Location | Snohomish, WA 98290 |
|---|---|
| Service | SasWash roof treatment plus a small tune-up |
| Inspection | October 13, 2026: attic and roof |
| Roof | Gray laminate asphalt shingles with plastic box vents and pipe flashings, on a two-story home |
| Condition found | Moss in the joints between shingle tabs, moss and lichen on the box vents, growth along a wall line and the hips |
| Tune-up | Small tier (up to 20 squares): sealant over vent and pipe flange fasteners, exposed nail heads, vent flange corners, and a wall flashing |
| Roof size | Not recorded beyond the tune-up tier |
| Schedule | Inspection October 13; treatment and tune-up October 27, 2026, one visit |
| Project investment range | $2,500 to $4,000 |
What Squatch Found on the Inspection
The inspection on October 13, 2026 started in the attic, where the air handler and ducting sit under the roof deck, then moved to the roof.
- Box vents: the tops of the plastic box vents were coated in green moss and lichen, with moss clumps on the shingles at their flanges and packed underneath the hoods.
- Shingle joints: moss was growing in the joints between the shingle tabs across the slopes.
- Hips and walls: dark growth ran down the hip lines, and a step flashing at a wall had yellow lichen on it.
- Pipe flashings: the plumbing vents had Oatey FlexFlash flashings, with small moss clumps beside them.
Why We Recommended SasWash and a Tune-Up
The growth sat on the surface: in the tab joints, on the vent hoods, and along the hips and wall lines. Squatch quoted two line items, The SasWash and a small tune-up for roofs up to 20 squares, and the homeowner approved both.
How the Visit Went
October 27, tune-up: the crew worked across the roof first. The box vents and pipe flashings in the photos got sealant over their flange fasteners, and exposed nail heads in the field got white sealant dabs. Before the wash, the crew also photographed a strip of yellow-green growth along the shingle courses at the base of a wall.
October 27, SasWash: the solution was sprayed across the slopes with a wand, and the photos show it running down the courses toward the gutters. After the wash, the crew added white sealant at the corners of the vent flanges and on the fasteners of a wall flashing.
The Result
The completion photos were taken while the roof was still wet with the solution, and there is no later dry photo in the job file, so this record shows the treatment going on rather than a dried, cleared roof. What the file does show is the vent and pipe flanges sealed, the exposed nail heads covered, and the slopes treated in one visit.
What This Treatment Cost
Project investment range: $2,500 to $4,000. 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.
The invoice carries the same two lines as the quote, The SasWash and the small tune-up. The tune-up line is the small tier, labeled for roofs up to 20 squares.
What Homeowners With Similar Roofs Should Know
Look at the vents. On this roof the heaviest growth was on and under the plastic box vent hoods, more than on the open shingles.
A cleaning visit is a chance to seal. The tune-up here was mostly sealant: flange fasteners, exposed nails, and a wall flashing, done in the same trip as the wash.
Related questions
How much did this SasWash treatment in Snohomish cost?
The project investment range was $2,500 to $4,000 for a SasWash roof treatment plus a small tune-up. The range reflects this project’s scope and is not a current quote.
What did the tune-up include on this roof?
Sealant over the flange fasteners on the box vents and pipe flashings, white sealant dabs over exposed nail heads, and sealant at the vent flange corners and on a wall flashing’s fasteners after the wash.
Where was the moss on this roof?
In the joints between shingle tabs, on and under the plastic box vent hoods, along the hip lines, and along the courses at the base of a wall. A step flashing at a wall also had lichen on it.
How long did the treatment take?
One visit on October 27, 2026 covered both the tune-up and the SasWash treatment. The inspection was two weeks earlier, on October 13.
Have a roof with similar symptoms?
If you see moss in the shingle joints or on your vents, Squatch Roofing can run a free 21-point inspection, show you the photos, and tell you whether a SasWash treatment, a Roof Maxx treatment, or a repair fits your roof. Squatch serves Snohomish, Mill Creek, and the greater Seattle area. Related projects: the Kirkland SasWash with a roof anchor and the Snohomish roof and gutter replacement. 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, November 2026. Technical review by Ben Metsker, Manager, Squatch Roofing.
