Roof Cleaning in Sammamish
Up on the Sammamish Plateau, a few hundred feet above the lake, winters run a little colder and frost sits on the roof longer. Large homes in Trossachs and Klahanie have big roof areas, and the slow-drying north sides are where moss spreads first.
Frost and slow drying are spreading moss across big roofs
On the plateau, roofs start many winter days frosted and stay damp well into the afternoon. Moss thrives on that, and on a large roof it can spread across hundreds of square feet before anyone notices it from the ground.
Gentle roof cleaning, never pressure washing
Starting at $200 We inspect the full roof, clear moss and debris gently, then apply a roof-safe treatment that kills moss and algae at the root. Anything that comes down into the gutters or onto the ground goes into your yard-waste bin before we leave, and anything extra leaves with us.
A big roof that dries out on short winter days
With the moss and algae treated, even the north slopes shed rain and melting frost instead of holding it, and a large roof stops quietly losing ground to moss every winter.
A roof replaced years early costs far more than treatment
Skip treatment a season or two and granule loss keeps compounding, quietly shaving years off a roof that still had a decade left. Staying on a regular treatment cycle costs a fraction of what a new roof does.
Save on your first service — New customers get 10% off.
Save when you bundle — Request multiple services at once. Fewer trips reduce our carbon footprint and lower your bill.
Save when you subscribe — Repeat every 1, 3, 6, or 12 months.
What's included
- Roof inspection. We walk the roof first to check for existing damage and note anything fragile before treatment starts.
- Gentle cleaning. Moss and debris are cleared gently, without a pressure washer or anything that scrapes the shingles.
- Moss treatment. A roof-safe moss treatment kills moss, algae, and lichen at the root, and keeps working with the next rains.
- Ground-level check. We clear gutters and walkways of anything that washed down and put it in your yard-waste bin (anything that doesn't fit is bagged and taken away), then do a final walk-around to check the shaded, high-buildup slopes.
Worth knowing
Older or already-brittle shingles can be more fragile underfoot, and moss that's been established for years may have already lifted or damaged shingles beneath it. We'll let you know if we spot anything like that before we start, rather than treat over a problem that needs a roofer instead.
Frequently Asked Questions
Our roof is big and hard to see from the ground. How do we know if it needs treatment?
Look for green on the north side, black streaks, or moss washing into the gutters after rain. Or text us a few photos, including the back of the house, and we'll tell you what we see.
Do you clean up the gutters after treating the roof?
We clear anything the treatment washes into the gutters before we leave. If the gutters already need a full cleaning, it's easy to book both in the same visit.
Will this damage my shingles the way pressure washing would?
No — we never pressure wash roofs. High-pressure water strips the protective granules off asphalt shingles and can void your roofing warranty. We clean gently, without pressure washing or scraping, and a roof-safe moss treatment does the rest, so moss and algae come off without damaging the roofing material underneath.
How often does a roof need moss or algae treatment?
Most Eastside roofs benefit from treatment every 1-2 years. Shaded, north-facing slopes under trees tend to need it more often than sun-exposed sections, since moss spreads fastest wherever moisture lingers.
Other services in Sammamish
- Gutter Cleaning
- Move-Out Cleaning
- Driveway Pressure Washing
- Patio & Deck Washing
- Siding & House Washing
- Fence Washing
- Window Cleaning
Roof Cleaning in other Eastside cities
Roof Cleaning across the Eastside · All services · Our service area