What Are the Black Streaks on Your Roof?

Black streaks on roofs are typically caused by a type of algae called Gloeocapsa magma. This algae thrives in humid environments like Clarksville and feeds on the limestone filler used in asphalt shingles.

As the algae spreads, it creates dark streaks that run down the roof, especially on areas that receive less sunlight.

Homes in Clarksville often see this problem develop on north-facing slopes and shaded sections of the roof.

Why Roof Algae Is a Problem

While the streaks may look like a simple cosmetic issue, algae growth can lead to bigger problems over time.

Roof algae can:

• trap moisture against roofing materials
• contribute to premature shingle deterioration
• spread across the roof surface if untreated
• reduce curb appeal and property value

The longer the algae is left untreated, the more difficult it becomes to fully remove.

What NOT to Do

Many homeowners try to solve the problem themselves—but this often causes more harm than good.

Avoid:

• using high-pressure washing (can damage shingles)
• scrubbing shingles (removes protective granules)
• using harsh chemicals not designed for roofing materials

Improper cleaning can shorten the life of your roof and lead to costly repairs.

The Right Way to Remove Black Roof Streaks

The safest and most effective method is soft washing.

Soft washing uses:

• low-pressure application
• roof-safe cleaning solutions
• targeted treatment to kill algae at the source

This process removes existing streaks and helps prevent regrowth without damaging roofing materials.

Professional Roof Cleaning in Clarksville, TN

Exterior Solutions provides professional roof soft washing in Clarksville designed specifically to remove black streaks and algae buildup safely.

Our process:

• eliminates algae at the source
• restores the appearance of your roof
• protects your shingles from damage

If your roof is showing signs of black streaking, professional cleaning is the safest and most effective solution.

When Should You Clean Your Roof?

If you’re starting to notice:

• dark streaks forming
• uneven discoloration
• algae growth spreading

…it’s time to take action before the problem worsens.

Serving Clarksville and Nearby Areas

Exterior Solutions provides roof cleaning services throughout:

Clarksville
Sango
Pleasant View
Adams
Oak Grove
Hopkinsville