Roof Cleaning Warranty in Oregon: What Voids It and What Keeps It Safe
If you are thinking about getting your roof cleaned in Eugene, one worry usually comes first: will cleaning void my shingle warranty? The honest answer is that it depends entirely on the method. Soft washing — low pressure with a manufacturer-approved cleaning solution — is the method shingle makers point to. Pressure washing is the method that gets warranties voided. This guide explains, in plain English, what your warranty actually says about cleaning, what voids it, what a moss-treatment warranty should cover, and the six questions to ask any Eugene contractor before you hire them.
Quick Answer
Soft washing does NOT void a shingle warranty — it is the cleaning method approved by the Asphalt Roofing Manufacturers Association (ARMA).
Pressure washing CAN void it — stripped granules count as homeowner-caused damage, not a manufacturing defect.
Moss itself does not void a warranty, but damage caused by moss left untreated is not covered either.
Always get the method in writing (PSI + chemical) before work starts.
What Your Shingle Warranty Actually Says About Cleaning
Shingle warranties from GAF, Owens Corning and CertainTeed cover manufacturing defects — shingles that fail because of how they were made. They do not cover damage caused after installation, and that is where cleaning method matters. ARMA, the industry association for asphalt roofing manufacturers, specifies low-pressure washing with a chlorine-based solution as the approved method for removing algae and moss. A soft wash uses 50–150 PSI, a sodium hypochlorite solution of about 3–6% with a surfactant, and a dwell time of around 30 minutes before a gentle rinse. That is well inside what manufacturers accept. What manufacturers do not accept is high pressure on asphalt shingles. Pressure washing strips the protective granule layer, shortens the roof’s life, and turns a warranty claim into a denied claim — because the damage was caused by the cleaning, not by the shingle. The same logic applies to aggressive scraping and wire brushing, which gouge granules off in the same way. Learn how soft wash vs pressure wash methods compare, and why roof soft washing is the safer choice for shingles.
5 Things That Can Void Your Roof Warranty
- Pressure washing — granule loss is treated as homeowner-caused damage by GAF, Owens Corning and CertainTeed.
- Aggressive scraping or wire brushing — removes granules and can crack brittle shingles, especially on older Eugene roofs.
- Unapproved coatings and sealants — products the manufacturer never tested can trap moisture and void coverage; never let a contractor seal your roof without written manufacturer approval.
- Foot-traffic damage — careless walking cracks shingles and breaks seals; a careful crew plans its path and works from ladders and ridges where possible.
- Ignoring moss damage — moss itself does not void a warranty, but leaks and rot caused by moss left in place for years are maintenance failures, and maintenance failures are not covered.
What a Moss-Treatment Warranty Should Cover
A treatment warranty is different from a shingle warranty. It is the cleaning company’s own promise, and it should be in writing. A fair one covers regrowth: if moss returns within the promised window — commonly 12 months, sometimes longer with an annual maintenance plan — the company re-treats at no extra charge. It should state the window in months, whether re-treatment includes a full re-clean or a chemical re-application, and what is excluded: new debris piles, overhanging branches that were never trimmed, and storm damage are normal exclusions. Be sceptical of ‘lifetime’ treatment warranties with no conditions in writing — moss grows back in Eugene’s 47 inches of annual rain, and any promise that ignores that is marketing, not a warranty. Ask for the warranty document before you pay, not after. See our moss treatment service for what a written treatment promise should look like.
Vet Any Eugene Contractor With These 6 Questions
- Are you licensed with the Oregon Construction Contractors Board (CCB), and can I see the license number?
- Can you show me a current certificate of insurance, and what liability limit does it carry?
- What exact method will you use on my roof — PSI, chemical mix and dwell time — and will you put it in writing?
- How do you protect plants, pets and gutters during treatment?
- Is a regrowth warranty included in writing, and for how many months?
- Will I get a written quote and before-and-after photos?
Any contractor who cannot answer all six clearly is not the contractor to trust with your warranty. A typical Eugene soft wash costs $300–$600. Prices checked October 2026. See roof cleaning cost details, browse our services, or contact us for a written quote.
Oregon CCB Licensing: What It Means and How to Check
In Oregon, most residential contractors must be licensed with the Oregon Construction Contractors Board (CCB). A CCB license means the contractor has met the state’s bonding, insurance and education requirements — it is the single fastest trust check a homeowner has. You can verify any contractor’s license on the Oregon Construction Contractors Board website. We claim no license number on this page: licensing belongs to the company you hire, and verifying it takes two minutes. If a contractor cannot be found in the CCB lookup, or asks you to skip permits or paperwork, walk away.
Frequently Asked Questions
Does soft washing void my roof warranty?
No. Soft washing at 50–150 PSI with a chlorine-based solution is the method ARMA specifies for algae and moss removal, and it does not void a GAF, Owens Corning or CertainTeed shingle warranty. Pressure washing is the method that risks a voided warranty.
What if a contractor already pressure-washed my roof?
Check for granule loss in your gutters and downspouts, photograph it, and ask the contractor in writing what they will do about it. A manufacturer will usually treat granule stripping as homeowner-caused damage, so your remedy is with the contractor, not a warranty claim.
Are lifetime moss-treatment warranties real?
Treat them with scepticism unless the conditions are in writing: the regrowth window in months, what re-treatment includes, and what is excluded. In Eugene’s wet climate moss always tries to return, so an unconditional lifetime promise is rarely what it sounds like.
Does moss itself void my warranty?
No, but damage caused by moss left untreated – leaks, rot, lifted shingles – is a maintenance failure, and maintenance failures are not covered. Cleaning the moss protects both the roof and the warranty.
I rent my home out — who should hire the roof cleaner, landlord or tenant?
The property owner should arrange and approve roof work, since the warranty and the roof asset belong to them. Tenants should report moss or leaks promptly and leave contractor selection to the owner.
Does my roof warranty transfer if I sell my home?
It depends on the manufacturer and the shingle line — many GAF, Owens Corning and CertainTeed warranties transfer once to a new owner, sometimes with conditions or a transfer fee. Check your warranty document or ask the manufacturer before listing the home.
Request a Free Roof Inspection
Get a written quote, the cleaning method in writing, and a clear answer on what it means for your warranty — before any work starts.