Professional Roof Restoration That Extends the Longevity of Your Shingles

Protect your home’s most important asset with our eco-friendly, "no-pressure" treatment that kills moss at the root and prevents avoidable structural damage. Our specialized process doesn't just clear the surface; it preserves the integrity of your shingles and restores their original color, extending the life of your roof while dramatically elevating your curb appeal.

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Professional Roof Cleaning & Moss Treatment: Serving All of King County

Is moss starting to take over your roofline and degrade your shingles? In our damp PNW climate, moss isn't just an eyesore; it’s a threat to your roof's structural integrity. Our eco-friendly, "no-pressure" treatment kills moss at the root and halts damage without the risk of shingle loss. We preserve your roof's lifespan and restore its original color, protecting your home’s biggest investment for years to come. Don't just treat the moss, save your roof.

Roof Preservation: Stop Moss From Cutting Your Shingle Lifespan

In Western Washington, moss isn't just an eyesore; it’s a biological threat to your roof. Moss acts like a sponge, holding moisture against your shingles which leads to wood rot, shingle lifting, and eventual leaks. Quality asphalt shingles can last an average of 30 years in the PNW; however, moss is a direct threat to that lifespan and can shave 5 to 10 years of usable life off the roof.

A $20,000 premature roof replacement is often avoidable with the right care. Our specialized, "no-pressure" treatment kills moss at the root and prevents it from returning. By treating the moss growth now, you are making a smart, cost-effective investment in the long-term health of your home’s most critical defense.

Roof Cleaning: Our Professional 7-Step Process

At Priority Washing Services, we’ve developed a 7-step restoration process specifically for the heavy moss growth found in the Pacific Northwest. By combining manual extraction with eco-certified treatments, we ensure your roof is protected, the moss is killed at the root, and your property’s look is fully restored. This treatment not only cleans your roof but actively extends the lifespan of your shingles.

  1. Structural Health Audit We act as your eyes on the roofline. Before beginning, we perform a thorough audit of your roof’s condition to identify soft spots, compromised shingles, or failing flashings. We only proceed once we’ve validated that your roof is healthy enough for professional cleaning.

  1. Manual Moss Extraction We avoid the "pressure-wash trap" that strips shingles of their protective granules. Our team uses speciale brushes to manually agitate and remove large moss clusters. This targeted, hands-on approach clears the bulk of the growth while preserving the lifespan of your roof.

  2. Roof Blow-Off Once the moss is loosened, we perform a full blow-off of the entire roof surface. We clear all loose organic debris, pine needles, and dust from your roof’s valleys, planes, and ridges, preparing the surface for a deep treatment.

  3. Complete Gutter & Downspout Service Roof cleaning is a messy process, but we don't leave that mess for you. We manually scoop all debris that has migrated into your gutters during the cleaning. We then flush the downspouts to ensure your drainage system is functioning at 100% capacity.

  4. Eco-Certified Treatment Application o prevent moss from returning, we apply a commercial-strength algaecide that is OMRI-Listed and NSF/ANSI/CAN 60 Certified. This is a professional-only formula you won't find at a big box store; it is designed to kill microscopic roots and sanitize your shingles without the use of harsh, corrosive chemicals.

  5. Zero-Trace Property Restoration We treat your property with respect. Once the roof is treated, we rake up the large moss debris from your landscaping and perform a thorough blow-off of all entryways, decks, and hard surfaces. We finish with a targeted rinse of siding and walkways as needed to leave the ground looking as good as when we arrived.

  6. Digital Quality Proof We provide you with high-resolution photos of the completed work. Since you shouldn't have to climb a ladder to see the results, our "Photo Proof" process gives you total peace of mind that every peak and valley has been professionally serviced.

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Trusted Local Gutter Experts in Your Neighborhood

Issaquah
Mercer Island
Sammamish

Based in Issaquah, we are a locally owned business that understands the specific maintenance needs of Eastside communities. Select your city below to see our local work and specific pricing for your area:

Bellevue
Sammamish
Kirkland
Redmond
Renton
North Bend
  • In our wet Western Washington climate, moss acts like a sponge, holding moisture against your shingles. During the winter, this water freezes and expands, prying shingles apart and causing wood rot underneath. Removing moss isn't just about curb appeal—it’s about preventing a premature $20,000 roof replacement.

  • Never. High-pressure washing is the fastest way to ruin a roof by stripping away the protective UV granules and forcing water under the shingles. We use a "soft-treatment" approach: manual brushing to remove the bulk of the moss, followed by a professional-grade algaecide to kill the remaining roots.

  • Yes. We use a commercial-grade algaecide that is OMRI-Listed (certified for organic use) and NSF/ANSI/CAN 60 Certified. It is significantly safer than the harsh, corrosive bleach-based cleaners used by many competitors.

  • Our manual brushing removes the heavy moss clusters immediately. After we apply our certified treatment, any remaining microscopic roots are killed. Over the next few rain cycles, any tiny remnants will naturally weather away, leaving your shingles sanitized and clear.

  • While effective at killing moss, common products like Moss Out or Moss B Ware often use zinc or iron sulfates. These are "Big Box" solutions that carry significant risks: they are toxic to fish and aquatic life in our local waterways, can stain your concrete driveways, and may even corrode copper or aluminum gutters.

    Priority Washing Services uses a professional-strength algaecide that is OMRI-Listed and NSF/ANSI Certified. It is a better, more responsible choice for King County homeowners who want a clean roof without risking the health of their pets, plants, or the local ecosystem.

  • No. We use a modern management system that sends you text or email updates when we arrive and when we finish. We provide high-resolution photo proof of the completed work and electronic invoicing, allowing you to manage your home maintenance while you're at work or running errands.

  • Due to our consistent moisture levels and dense tree canopy, we recommend a professional treatment every year, or at a minimum, every two years. For homes located in heavily shaded areas or near regional landmarks like Tiger Mountain and the Issaquah Alps, we strongly suggest an annual "check-up." Regular maintenance allows us to stop moss growth before it can establish a deep root system, ultimately saving you from the cost of aggressive manual removal in the future.

  • Our process follows the Asphalt Roofing Manufacturers Association (ARMA) guidelines. By avoiding high-pressure washing and using certified, non-corrosive cleaning solutions, we help maintain your roof's warranty and extend its overall lifespan.

  • Priority Washing Services serves the entire King County region, including Seattle, Bellevue, Issaquah, Sammamish, Redmond, Renton, Kent, and the Snoqualmie Valley. If you are a King County resident, our team is equipped to handle your roof restoration.

  • Yes, fully. Roof work carries significant liability. Hiring an uninsured individual is a major risk for a homeowner. We carry comprehensive liability insurance and bonding specifically for roof-level work, ensuring both our team and your property are 100% protected.

By Choosing Priority Washing Services, You’ll Experience Professional Home Care

Fully Licensed & Insured

30 Day No Clog Guarantee

Easy Scheduling
+
Recurring Service Packages

Apple Pay Accepted

Client Portal To Manage Appointments and Service Records

Explore All of Our Professional Cleaning Services

Pressure Washing
Window Washing
Soft Washing
Gutter Cleaning
Moss Out and Moss B Ware Toxic

We use sustainable, commercial grade algaecide treatments

Did You Know? Zinc and copper based chemicals are toxic to us and our local aquatic ecosystems. Our only product we us is NSF/ANSI 60 & OMRI Listed. Making it a better alternative.

Not toxic big box store chemicals that lack results

Grean Clean Pro Algaecide

Why King County Homeowners Trust Priority Washing Services for Roof Care

When you choose Priority Washing Services, you’re partnering with a licensed, bonded, and insured local business that understands the specialized techniques required to protect your roof from the damage often caused by inexperienced cleaning. Our professional equipment and certified technicians allow us to tackle everything from light algae staining to heavy moss infestations with precision and care.

We focus on the long-term health of your roof. We offer flexible Professional Maintenance Plans, including annual treatments designed to stop moss before it can take root. With us, you aren't just getting a cleaner roof; you're making a smart investment in your home’s structural integrity and preserving your shingles for years to come.