Roof Cleaning & Moss Removal

What it is & how it works

Roof Cleaning & Moss Removal in plain English

In the Pacific Northwest, moss, algae, needles and leaf litter are a roof's worst enemy. We scrub it off by hand and follow with a spray-on moss treatment — never a pressure washer — so your shingles keep shedding water the way they were built to and your roof lasts as long as it should.

Why cleaning matters for roof longevity: moss acts like a sponge. It holds water against your shingles for days after every rain, pushes shingle edges up so wind-driven rain gets underneath, and its roots work into the seams and slowly break down the asphalt and granules. Needles and debris piled in valleys and behind chimneys dam water and rot the decking below. Left alone, a Seattle roof that should last 25 – 30 years can fail in 15. Our process: we inspect the roof first and photograph problem areas, scrub the moss and debris off by hand with brushes — across the surface, in the valleys and around penetrations — then spray a roof-safe moss treatment over the roof that kills moss and algae down to the roots, and let the rain rinse away what's left over the following weeks. We finish by clearing everything out of your gutters and downspouts, and can install zinc strips along the ridge to slow regrowth. Because we're roofers, not just cleaners, we'll also flag any lifted shingles, cracked pipe boots or flashing issues we spot while we're up there.