Those dark streaks running down many North Texas roofs are usually algae, not dirt. Cleaning them the wrong way can shorten the life of your shingles. Here is how to clean roof shingles safely.
The Short Answer
Clean asphalt shingles with a low-pressure soft wash: apply a cleaning solution that kills algae, let it work, and rinse gently. Never use a high-pressure washer on shingles. High pressure can knock off the protective granules and loosen shingles.
Why Not to Pressure Wash Shingles
Asphalt shingles are covered in small granules that protect them from the sun. A high-pressure stream strips those granules away, which can age the roof faster. It can also drive water under the shingles. The cleaning solution, not pressure, is what removes the algae.
What Causes Black Streaks on Shingles?
The streaks are typically a type of algae that feeds on the limestone filler in many shingles. It spreads across the roof over time and holds moisture. Learn more in why roofs get black streaks.
How to Clean Roof Shingles Step by Step
1. Put safety first
Roof work is dangerous. Use proper fall protection, avoid wet or steep roofs, and consider whether the job should be done by a professional.
2. Protect plants and the area below
Wet down landscaping before and after, and cover delicate plants.
3. Apply a roof-safe cleaning solution at low pressure
Spray the solution evenly over the streaked areas so it can kill the algae.
4. Let it dwell
Give the solution time to work. Many streaks fade as the algae dies.
5. Rinse gently
Rinse with low pressure, and rinse the plants and ground below again.
Moss vs. Algae
Moss is thicker and grows in clumps, often on shaded roofs. It needs a different approach than algae streaks. See how to remove moss from a roof.
When to Call a Pro
For most homeowners, a professional roof washing service is safer and faster. We soft wash roofs across DFW, and most roofs cost $300 to $600. Read more about soft wash roof cleaning and roof cleaning cost.
Ready for a quote? Call 817-580-9881 or request a free estimate online. We serve Arlington, Fort Worth, Dallas, Grand Prairie, Mansfield, and the rest of our DFW service areas.
FAQs
Can you pressure wash roof shingles?
No. High pressure can strip the protective granules from asphalt shingles and force water underneath. Shingles should be cleaned with a low-pressure soft wash.
What is the best way to clean roof shingles?
Apply a roof-safe cleaning solution that kills algae at low pressure, let it dwell, then rinse gently. This removes black streaks without damaging the shingles.
What are the black streaks on my roof?
They are usually algae that grows on asphalt shingles and spreads over time, especially on shaded parts of the roof.
How much does it cost to clean roof shingles?
In the Dallas-Fort Worth area, most professional roof washing jobs cost $300 to $600 depending on the roof’s size, pitch, and staining.
