Before hiring a roof washing company, ask how it will clean your roof, protect your landscaping and manage runoff. Verify the crew’s experience and insurance, and get the scope and warranty in writing so you can compare what each quote includes.
Table of Contents
- What causes those black streaks on a roof in the first place?
- Does roof washing actually damage shingles, or is that a myth?
- Field Notes from Chris Negley
- What happens to my landscaping, gutters, and patio during a roof wash?
- How do I verify a roof washing company’s experience and insurance?
- What should a written roof washing warranty actually cover?
- How does Elegant Estates of the Fingerlakes approach a roof wash?
- What should I ask before I sign a roof washing estimate?
- Key Takeaways
- References
What causes those black streaks on a roof in the first place?
Brown or black streaks on asphalt shingles are often caused by algae, especially in areas that stay damp or shaded. The Asphalt Roofing Manufacturers Association identifies Gloeocapsa magma as a common cause of this discoloration.
A roof with dark streaks may still have plenty of service life left. An assessment can help determine whether cleaning is appropriate for the roof’s condition.
Moss, lichen, and algae respond differently to cleaning. Moore’s Pressure Washing also notes that metal, wooden, and asphalt roofs each present different cleaning considerations.
Results can vary with shingle age, roof slope, and how long the growth has been there. A roof that has carried heavy staining for years may still show some discoloration after the growth has been treated.
Does roof washing actually damage shingles, or is that a myth?
The Asphalt Roofing Manufacturers Association advises against using a power washer on asphalt roofing. Ask the contractor how their method follows the guidance for your specific shingles.
With a soft wash, the cleaning solution and dwell time do the work. At Elegant Estates, we use a non-pressure soft-wash process and keep high-pressure spray off the shingles.
High pressure can dislodge the protective granules on asphalt shingles. Losing those granules leaves the shingle surface more exposed to the elements.
Metal and wood roofs have their own cleaning considerations. Ask what method the crew will use on your roof and how they account for its material, finish, and fastening details.
Field Notes
Chris Negley
Owner, Elegant Estates of the Finger Lakes
What a cheaper roof wash can cost
A homeowner called us for a roof washing estimate. After visiting the property, I gave them a quote by phone for a non-pressure soft wash that included our Property Protection Plan. They passed on the roof wash and later called us back to look at a deck that needed repair and restoration.
When I arrived for the deck visit, another contractor was already cleaning the roof. I could see a technician standing on the roof, blasting the asphalt shingles with high-pressure water. I saw no steps being taken to protect the plants below. From where I stood, I couldn’t tell whether they had used a cleaning solution.
My first thought was that saving a couple hundred dollars up front could lead to thousands in roof repairs or an early replacement. High pressure can strip the protective granules from shingles and force water into seams, increasing the risk of leaks and shortening the roof’s service life.
What I’d ask before signing
Will anyone use high pressure on my shingles? How will you protect the plants below the roofline, and where will the runoff go? Ask for those answers in writing before you compare prices.
What happens to my landscaping, gutters, and patio during a roof wash?
Overspray and runoff can reach foundation plantings, lawns, gardens, patios, and sensitive finishes. Depending on the extent of the damage, replacing mature landscaping or repairing affected surfaces can cost hundreds or even thousands of dollars.
Ask where the downspouts discharge, how the crew will protect plants below the roofline, and what they’ll do if runoff starts reaching a sensitive area.
A protection plan starts with an inspection. Based on the property and the service, the crew may rinse landscape beds, use a detergent neutralizer, and take other precautions to manage overspray and runoff.
Ask the contractor to walk through the plan for your home before work begins. If gutter cleanout is included, ask for it as a separate line item so you can compare the scope of each estimate.
How do I verify a roof washing company’s experience and insurance?
Ask who will do the work and whether the crew has cleaned similar roofing materials and slopes. If your property has tight access or extensive landscaping, ask about jobs with those same conditions.
Ask to see photos from the company’s own jobs. Look for properties with similar roof pitch, shading, and landscaping, and ask what results the homeowners saw over time.
Request a current certificate of insurance. Confirm that the coverage applies to the proposed roof cleaning and ask about workers’ compensation where applicable. Ask what training the crew has for this type of work.
What should a written roof washing warranty actually cover?
Compare each warranty’s duration, what qualifies for a follow-up visit, any exclusions, and what the company will do if a covered issue returns. Ask for the current written terms before you accept the estimate.
How does Elegant Estates of the Fingerlakes approach a roof wash?
Elegant Estates of the Fingerlakes uses a non-pressure soft-wash process for roof algae, black streaks, and other biological growth, with an approach suited to the roofing material. Roof washing starts at $649 as of 2026.
Our Property Protection Plan starts with a site inspection. We select precautions based on the property and the work, which may include landscape rinsing and detergent neutralization. Ask us to walk you through how we’ll manage runoff and overspray at your home.
Elegant Estates publishes a three-year roof washing guarantee. Review the Terms and Conditions and ask for the current written warranty so you can compare coverage, exclusions, and follow-up terms with other estimates.
We can assess whether rust, mineral deposits, or efflorescence are candidates for specialty stain removal, listed from $149 as of 2026. Results depend on the stain, the surface, and how long it has been there.
Gutter cleaning is available as a separate service. If you’d like it done during the same visit, ask to have it itemized on your estimate.
What should I ask before I sign a roof washing estimate?
A detailed proposal should spell out the areas being cleaned, the protection steps, what you should move or prepare, and whether gutter cleanout is included as a separate line item.
Ask how the crew handles weather delays and how they’ll let you know if they discover an existing roof or gutter issue during the job.
Look for reviews from roof-wash customers who mention plant protection, cleanup, communication, and follow-through.
Have the contractor explain what’s causing the discoloration, what results to expect, and how the roof’s appearance may change in the weeks after treatment.
Key Takeaways
- Dark streaks are often caused by algae. Ask what’s causing the discoloration and what results to expect.
- High pressure can dislodge protective granules and shorten the service life of asphalt shingles.
- Ask how the crew will protect landscaping and manage runoff from gutters and downspouts.
- Request a current certificate of insurance and confirm that it covers the proposed roof cleaning.
- Compare written warranties by duration, exclusions, and what the company will do if a covered issue returns.
