Roof Cleaning Costs

A roof is designed to last as long as 25 or 30 years, provided that it is well-maintained. For roofs that have a lot of overhang or that don’t get enough natural light, regular cleaning may be part of that maintenance. Dark streaks, algae growth, and other signs of debris buildup aren’t always signs that you need a new roof-- you might just need roof cleaning services.

Roof cleaning will only need to be done once every 10 years or so, depending on the environment of your property. The cost of roof cleaning depends on the amount of moss or mildew buildup, the size of the roof, and the complexity of its design. A simple flat or sloped roof will be cheaper to clean than an intricate roof with multiple pitches and angles to consider.

Roof cleaning: by roof type.

Roof cleaning: a simple sloped roof that measures 1,500 square feet with mild debris and dirt buildup.

Other considerations and costs

• Typical cleaning jobs take between two and five hours to complete. Some companies charge an hourly rate for their service while others may charge a job or service rate.
• Professional cleaners have the right tools and materials to provide the safest cleaning for the roof material, regardless of the type of roof that you have. Since cleaning is about five percent of the cost of a roof replacement, it’s best to leave it to the professionals.
• Companies that offer to power wash your roof should be avoided. The Roofing Institute of America and other professionals advise that this type of cleaning can potentially lead to damage to shingles or other roofing materials.
• The type of roof material will affect the cost of cleaning, as different methods and cleaners are required. Special tools may also be necessary for certain jobs, and this may incur a premium charge. 
• Physical scraping may be required for some roofing materials. This can increase labor costs and require more man-hours for the work to be completed.

DIY considerations

• Never use DIY or homemade roof cleaning solutions. These can be dangerous to the roof and potentially toxic to the people in your home. If you choose to attempt DIY roof cleaning, use the appropriate cleaning products (such as asphalt roof cleaner) found at your local hardware store.
• If you insist on using a hose on the roof, use a garden hose. Nothing more than a “normal” spray setting (about 30 PSI) should be used on this surface.
• Check your roof warranty regarding cleaning to ensure that a DIY cleaning isn’t going to void any guarantees or protections from the roofing installer.

References

• Craftsman Estimator Costbook, complete series year 2019.
• Latest prices found on Home Depot and other vendor Web sites.
• Literature review of DIY Web sites.