Not all roof stains are simply dirt. Many commercial and residential asphalt roofs develop black streaks caused by algae, organic growth, and environmental buildup. Left untreated, those stains can make a property look older, less maintained, and less professional from the outside.
In this recent project, Summit Professional Services completed a large-scale commercial roof washing and exterior cleaning project involving multiple buildings, staircases, vinyl siding, and concrete surfaces. Later in the day, our team also restored a set of weathered teak furniture and cleaned a small bluestone patio, showing how the right restoration process can improve a variety of exterior surfaces.
Watch the full project vlog below to see the roof washing and restoration process in action.
Related Services: Roof Washing | House Washing | Pressure Washing | Wood Restoration
What Causes Black Streaks on Asphalt Roofs?
Black streaks on asphalt roofs are commonly caused by Gloeocapsa magma, a type of blue-green algae that grows on roofing surfaces. This algae often appears as dark staining or streaking across roof shingles, especially in areas with moisture, shade, humidity, or nearby tree coverage.
On this commercial property, the roof had visible black algae streaks along with some lichen spots in certain areas. The goal was to treat the organic growth properly using a professional roof washing process rather than relying on high-pressure cleaning.
Why Soft Washing Is the Preferred Roof Cleaning Method
Asphalt shingles should not be cleaned with aggressive pressure. High-pressure washing can lift shingles, remove protective granules, and shorten the life of the roof.
Soft washing uses a controlled cleaning solution, low pressure, and proper application techniques to treat organic growth at the source. Instead of blasting the surface, the cleaning solution does the work by breaking down and killing algae, lichen, and other contaminants.
For this project, Summit Professional Services used a low-pressure roof washing method with a high-flow application. This allowed the cleaning solution to be applied evenly and thoroughly while reducing the risk of damaging the asphalt shingles.
Protecting Landscaping and Surrounding Areas
Before applying any roof cleaning solution, surrounding areas need to be protected. This includes plants, siding, walkways, exterior fixtures, and any surfaces that are not intended to interact with the cleaning solution.
During this project, the team heavily saturated nearby plants and surrounding areas with water before spraying. Keeping landscaping and exterior surfaces wet is an important part of risk management during any roof washing or soft washing project.
Proper preparation helps reduce the chance of unwanted chemical interaction and helps keep the property protected throughout the cleaning process.
Using Proper PPE During Roof Washing
Professional roof washing requires the right safety precautions. When applying roof cleaning solutions on a hot sunny day, certain chemicals can off-gas, which makes proper protective equipment especially important.
For this project, the team discussed the importance of using PPE, including nitrile gloves and a P100 respirator, while spraying asphalt roofs. This helps protect the crew during application and reinforces the importance of following professional safety standards on every job.
How the Roof Cleaning Solution Was Applied
Application technique matters. On this commercial roof washing project, the team applied the solution in a downward or horizontal pattern. They avoided spraying upward because spraying up can increase the risk of lifting shingles or forcing solution under roofing materials.
The cleaning solution was applied at very low pressure, around 100 PSI, while using a high flow rate to cover the surface thoroughly. The team used a higher soap concentration to help the solution cling to the roof and increase dwell time.
That dwell time is important because it allows the solution to actively treat and kill the black algae. With proper application, black algae is often remediated effectively and can show major improvement as the treatment continues to work.
The Difference Between Roof Washing and Pressure Washing
Roof washing and pressure washing are not the same thing.
Pressure washing is useful for certain hard surfaces, such as concrete pads, patios, and some exterior flatwork. Roof washing, however, requires a softer and more controlled approach.
With roof soft washing, the goal is to treat the growth without damaging the roofing system. This is why professional roof cleaning relies on the right cleaning solution, proper dwell time, careful application, and low-pressure equipment.
Additional Exterior Cleaning Completed on the Property
This commercial project included more than roof washing alone. The team also addressed vinyl siding, staircases, and concrete pads throughout the property.
Commercial properties often require a broader exterior cleaning plan because multiple surfaces contribute to the overall appearance of the building. Roof stains, dirty siding, stained concrete, and algae-covered stairs can all affect curb appeal, safety, and property presentation.
By combining roof washing with other exterior cleaning services, property owners and managers can create a cleaner, more professional appearance across the entire site.
Teak Furniture Restoration and Bluestone Patio Cleaning
After completing the Rhode Island roof washing project, the team returned to Massachusetts for a smaller restoration job involving teak furniture and a bluestone patio.
Teak is a high-quality wood that can develop biofilm, surface contamination, and weathered discoloration over time. For this project, the team gently cleaned the teak furniture with the grain, using the right chemistry and a practical approach to remove light organic buildup without being overly aggressive.
The furniture was then neutralized and rinsed, allowing the natural orange and warm wood tones to come back through. The result was a cleaner, more natural-looking finish that helped restore the furniture’s appearance.
The bluestone patio was also rinsed down as part of the project, improving the surrounding outdoor living space and creating a more polished final result.
Benefits of Professional Roof Washing for Commercial Properties
Commercial roof washing can provide several important benefits for property owners, facility managers, and business owners.
- Improves curb appeal and property appearance
- Removes black algae streaks and organic staining
- Helps maintain a cleaner and more professional exterior
- Uses a safer low-pressure process for asphalt shingles
- Supports long-term exterior maintenance planning
- Can be combined with siding, concrete, and stair cleaning
For commercial properties, exterior cleaning is not just about appearance. A clean, well-maintained building can help create a better first impression for tenants, customers, employees, and visitors.
Why Property Managers Choose Summit Professional Services
Summit Professional Services provides professional roof washing, soft washing, pressure washing, house washing, and wood restoration services throughout SouthCoast Massachusetts, Rhode Island, and surrounding areas.
Our approach focuses on surface preservation, safe cleaning methods, professional-grade equipment, and attention to detail. Whether we are cleaning a large commercial roof, restoring teak furniture, washing siding, or cleaning concrete surfaces, the goal is always to deliver a high-quality result while protecting the property.
Learn more about our exterior cleaning services:
Frequently Asked Questions About Commercial Roof Washing
What causes black streaks on asphalt roofs?
Black streaks are commonly caused by algae growth, especially Gloeocapsa magma. This growth often appears as dark staining across asphalt shingles and can become more noticeable over time.
Is pressure washing safe for asphalt shingles?
No, high-pressure washing is not recommended for asphalt shingles. It can damage the shingles, remove protective granules, and reduce the roof’s lifespan. Soft washing is the preferred method for roof cleaning.
How does soft washing remove black algae?
Soft washing uses a professional cleaning solution, low pressure, and proper dwell time to treat organic growth at the source. The solution breaks down the algae instead of relying on force.
Can roof washing be done on commercial buildings?
Yes. Commercial roof washing is an effective way to clean asphalt roofs, improve property appearance, and address black algae staining on larger buildings.
Do you also clean siding, concrete, and stairs?
Yes. Summit Professional Services provides a range of exterior cleaning services, including roof washing, house washing, pressure washing, concrete cleaning, and wood restoration.
Request a Commercial Roof Washing Estimate
If your commercial property has black streaks, algae growth, stained siding, dirty concrete, or other exterior buildup, Summit Professional Services can help restore and maintain your property with professional exterior cleaning services.
Contact Summit Professional Services today to schedule a roof washing or exterior cleaning consultation.
Summit Professional Services
“Revealing the Peak of your Residency”
774-319-6373
Helpful External Resources:
Asphalt Roofing Manufacturers Association: Algae Discoloration of Roofs
GAF Residential Roofing Shingle Resources
