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Roof cleaning & moss removal in Seattle

Safe, thorough roof washing that removes moss, algae and black streaks from asphalt shingle and metal roofs, then treats the roof to slow regrowth.

Why Seattle roofs need regular cleaning

Our long, wet season and shady evergreen canopy make Seattle one of the easiest places in the country for moss and algae to take hold on a roof.

Moss acts like a sponge. It holds water against your shingles, works its roots under their edges and gradually lifts them. Algae leaves the dark streaks you see running down many north-facing roofs, and lichen bonds tightly to the surface. All three shorten a roof’s life and send debris straight into your gutters.

Professional roof cleaning removes that growth without harming the roofing material, so your roof sheds water properly and looks the way it did when it was installed.

Signs your roof is due for a cleaning

Our roof moss removal process

1. Inspect and protect

We look over the roof, note any damaged shingles or flashing, and protect plants and walkways below.

2. Remove moss by hand

Thick moss is carefully brushed and scraped off with tools that won’t gouge shingles.

3. Soft wash the roof

A low-pressure cleaning solution breaks down algae, lichen and remaining spores, then is rinsed away gently.

4. Treat and clean up

We apply a moss treatment to slow regrowth, clear the gutters and downspouts of debris, and tidy the ground below.

Roof types we clean

Asphalt shingle roofs

The most common roof in the Seattle area. Cleaned with low-pressure soft washing to protect the granules that shield shingles from UV and water.

Metal roofs

Algae, pollen and oxidation are washed off with gentle methods that won’t scratch coatings or force water under seams.

Why not just pressure wash the roof?

High-pressure washing can strip shingle granules, force water under the roofing and void manufacturer warranties. It also removes the visible moss without killing the spores, so growth returns quickly. Soft washing and hand removal clean more thoroughly and are far easier on the roof.

Tip: Pair roof cleaning with gutter and downspout cleaning. Moss loosened from the roof always ends up in the gutters, and handling both in one visit saves you a second appointment.

Roof cleaning FAQs

How long does a roof cleaning take?

Most single-family homes take part of a day. Larger roofs or heavy moss can take longer; we’ll give you a time estimate along with your price.

When is the best time of year?

Late summer and early fall work well because moss is dry and easier to remove, and the treatment has time to work before the heavy rains. We clean roofs year-round when the weather allows.