There’s Moss on My Roof!
“There’s moss on my roof” is a frequent complaint we hear in the Northwest. Unfortunately, removing moss on roofs is a home maintenance job requiring special care. Despite its quaint appearance, what begins as a dusting of green leads to serious roof damage. Once moss gets thick enough to undermine shingles and cause decay, replacing the entire roof. Needless to say, that’s an expense any homeowner wants to avoid.


The Cause of Moss on Roofs
A roof that faces north gets little sunlight, or both are vulnerable to moss, especially in cool, damp climates like ours. Eventually, any roof that sits beneath a heavy tree canopy will likely develop moss. Growth begins as a thin layer of green that you can see from low angles.
Soon, the moss on roofs thickens and expands, working its way underneath the shingles. Often, the shingles get raised or even displaced. Moss growth is especially fast with wood shingles since the plant adheres quickly to porous surfaces. Consequently, removing moss from wood shingles is particularly difficult compared to composite or asphalt shingles.
Serious Damage That Spreads Fast
When moss on roofs becomes a thick mat, it behaves like a sponge that soaks up and holds moisture. Soon, the retained water seeps under and between shingles. Subsequently, the water flows to lower roof levels and eats away at its structure. Before you know it, the roof and its materials start to rot. This way, moss destroys a perfectly sound roof within a few months.
That is to say, fast removal of roof moss is critical to protect your roof and the entire structure of your home.
A Common Problem in the Pacific Northwest
Many homes in the Pacific Northwest develop moss on roofs. That’s because moss typically thrives in locations that are damp and shady. Consequently, most of your neighbors struggle with this problem, too. And as local business owners that began our company in 2016, we can attest that roof moss is a problem that requires regularly scheduled maintenance.
Of course, the level of service your roof requires depends on where you live and the nature of your surroundings. Once we schedule a visit, we assess precisely the professional treatment your particular roof requires. Our roof moss removal services include:
- Brush agitation to remove moss—NOT pressure washing
- An application of zinc monohydrate, or moss killer, which is totally eco- and pet-friendly
- Customized scheduled maintenance plans
- Affordable pricing
Free Estimates
The Dangers of Removing Moss from Your Own Roof
Balanced against getting a professional roof moss removal service, you can try to tackle the job yourself. On the negative side, roof moss removal is a dangerous, slippery job. It requires working on a roof that can be slippery or uneven in the best of circumstances. The addition of moss to the roof’s surface makes it downright treacherous. Therefore, we respectfully recommend you leave this job to the pros.
If you do decide to remove moss on roofs by yourself, don’t use a pressure washer. The high-powered jets will remove the protective granules on your shingles that repel water. Worse yet, the sheer force of a power washer can rip off shingles altogether, which leaves your roof even more vulnerable to water damage. Instead, you should use a long-handled, soft-bristle scrub brush to remove the moss. Work from the top of your roof to the bottom to avoid lifting, ripping, or breaking shingles.
How Often to Remove Moss on Roofs
Basically, you should remove moss from your roof when you can see growth from the ground level. In addition, if moss is blocking your gutters, have Rainier remove it immediately. Moss overgrows. The last thing you want is to wait before a small job becomes much bigger (and more expensive).
Ideally, it’s best to remove moss on roofs when it’s actively growing. Moss grows very little during the summer but thrives and spreads during damp spring and fall seasons. Therefore, the best time to remove moss on your roof is right before peak rains, when the moss is damp but no rain is forecast for a few days.
Can Weed Killer Remove Roof Moss?
We don’t recommend it. Lawn moss weed killers contain iron products, which leave rust marks. The best chemical products to treat roof moss kill the plant but won’t corrode your gutters or stain your roof.
How To Prevent Moss on Roofs
Without a doubt, the best way to keep roof moss from growing is through regular cleaning and maintenance. Our professionally trained crews have experience gently removing moss, so your roof remains intact. And after our careful air-brushing process, we treat your roof with eco- and pet-safe chemicals to inhibit further growth.
And while we’re treating your roof, we can give you an estimate for other home maintenance jobs. In addition to roof cleaning, we provide the following services:
- Gutter cleaning—prevent costly home repairs with clear, efficient gutters.
- Window cleaning—wake up to bright, unfiltered sunlight each and every morning.
- Power washing—keep your sidewalks and driveway pristine and clean.
As local business owners, we take pride in every job we get. Let us provide you with reliable, professional service.