Does Roof Cleaning Void Your Warranty?

Does Roof Cleaning Affect Your Shingle Warranty?

Soft washing does not void shingle warranties. High-pressure washing does. The Asphalt Roofing Manufacturers Association recommends a 50:50 mixture of laundry bleach and water applied and rinsed at low pressure, while GAF, CertainTeed, Owens Corning, and most other major manufacturers explicitly prohibit high-pressure washing, which strips the granules that protect the asphalt from UV. Whether roof cleaning affects your warranty depends entirely on the method used.

High-Pressure Washing: Voids Most Warranties

Most asphalt shingle manufacturer warranties explicitly exclude damage caused by high-pressure washing. The granule layer on asphalt shingles is bonded to the asphalt surface high-pressure water physically strips granules, which are the primary UV protection layer for the asphalt. Once removed, granule loss accelerates UV degradation of the asphalt base, dramatically shortening roof life. GAF, CertainTeed, Owens Corning, and most other major shingle manufacturers explicitly prohibit high-pressure washing in their warranty terms. A roof cleaned with a pressure washer by an unqualified operator may void its remaining warranty coverage.

Soft Washing: Compatible With Warranties

Soft washing low-pressure chemical application and rinse is the method the Asphalt Roofing Manufacturers Association (ARMA) recommends for cleaning asphalt shingles. ARMA’s published technical guidance states that a 50:50 mixture of laundry bleach and water applied with a low-pressure sprayer and rinsed with low-pressure water is the recommended approach. Most major manufacturer warranties are not voided by cleaning performed with this ARMA-recommended method. Confirm with your specific manufacturer’s warranty language if you are uncertain. (For more on this, see What Is Soft Washing and Why Is It the Right Method for Roofs?.)

Documenting the Cleaning

If your roof is still under manufacturer warranty and you are having it cleaned: get a written confirmation from the cleaning company that they use soft-wash method only and that no high-pressure equipment was used on the shingle surface. This documentation protects you if a warranty claim arises later and the manufacturer questions whether the roof was cleaned correctly. Keep it with your warranty documentation. (For more on this, see How to Find the Best Roof Cleaning Company.)

Roof Cleaning Cost at a Glance

Roof size: Larger roofs cost more due to more area to clean.

Roof pitch: Steeper roofs cost more for special equipment and safety measures.

Growth severity: Heavy moss, algae, or lichen means more work and higher cost.

Overall range: $400 to $1,200, averaging $700.

Planning Your Project Budget

The cost ranges in this article are based on industry data and are intended as planning benchmarks, not fixed prices. The actual cost for your project depends on your specific home, your local labor market, the current price of materials, and the scope the contractor confirms after a site inspection.

Always get at least two written quotes on equivalent defined scope before committing to any home services project. Wide price variation between quotes usually reflects differences in material quality, scope completeness (what is included and what is not), or contractor overhead and experience level rather than simple price competition.

Use the cost data in this article to ask better questions during the quoting process: What material is included? What does that per-square-foot or per-linear-foot rate include and exclude? Are permits, cleanup, and disposal included? What is the warranty on labor? These questions turn a quote into a comparable basis for decision-making. (For more on this, see Questions to Ask Before Hiring a Roof Cleaning Company.)

Working With a Contractor on This Project

Getting the right outcome on any home services project starts before the work begins. A few consistent practices make the difference between a smooth project and a frustrating one.

Get at least two or three quotes. A single quote gives you no basis for comparison. Two or three quotes reveal the market rate for the work, expose scope differences between bidders, and let you assess contractor communication quality before any commitment is made. The lowest bid is not automatically the best value if the scope is thin or the materials are underspecified.

Ask for licenses and insurance before work starts. Verify current general liability insurance and, for any work involving workers on your property, workers compensation coverage. Licensing requirements vary by state and trade; confirm the specific requirements in your jurisdiction. A licensed contractor who carries appropriate insurance protects both parties if something goes wrong during the project.

Get the scope in writing. A written proposal that specifies materials, labor scope, timeline, what is included (permits, cleanup, disposal), and warranty terms is the foundation of a professional engagement. Verbal agreements on any of these points invite misunderstanding. For any project over $500, written scope is non-negotiable.

Clarify the payment schedule upfront. A reasonable payment schedule ties major payments to project milestones: a deposit at signing, a payment at material delivery or project start, and a final payment at completion after a walkthrough confirms satisfaction. A contractor who requires full payment upfront before work begins is a red flag in any trade.