If you thought that layer of green developing of your roof was a good thing–think again. Moss can root itself onto the top layer of the granules on roof tiles, cutting down on the protection that shingles provide . We’ve even seen moss grow into the wood under the shingles, requiring the entire roof to be replaced. There’s something to think about!

So how to keep your roof moss free? In our experience, there’s no permanent solution. Big trees cast shade on a roof or deck, or drop needles and leaves, creating optimal conditions for moss spores. Even if you clean the moss off your roof, if your neighbor has them, the spores will just migrate back on to your roof.

So we recommend having your roof treated with an EPA-approved moss treatment, which will kill any existing moss and prevent re-growth for some time to come. If you’re serious about protecting your roof, then combine treatment with tree pruning and trimming branches which casts a shade on your roof. This will keep re-growth in check.

We never recommend pressure washing for roofs (unless they are tile) because it tears up shingles.

If you’re getting rid of moss to protect your investment in your roof, then use only a company licensed properly by the Oregon Department of Agriculture. There will be cheaper alternatives, but you might end up saving a buck today, to lose thousands on potential roof damage in the next couple of years.

Action Northwest is a licensed Commercial Pesticide Applicator through the Oregon Department of Agriculture.

If you’d like a free estimate for applying an EPA-approved moss treatment to your roof, click the button or give us a call at (503) 407-3346.

Request a Free Estimate

Request A Free Estimate

Select The Services You'd Like Estimated
(check all that apply)

Contact Info




Gutter or Downspout Installation
Gutter or Downspout Repair
Gutter & Downspout Cleaning

Windows Interior & Exterior
Windows Exterior Only
Window Track Detailing
Skylight Cleaning
Solar Panel Cleaning




Moss Remove & Treat w/ Gutter Clean Package
Moss Removal & Treatment
Moss Treatment Only
Roof Wash (Gentle Wash or Green Clean)
Algae Wash

Dryer Vent Cleaning
Roof Repair

Exterior Gutters
Driveway Cleaning
Concrete / Brick Walkway or Patio
House Wash (Gentle Wash Siding)
Wood / Vinyl Deck or Fence (Gentle Wash)