How to Properly Clean a Roof & Mitigate Algae Growth in Charleston

How to Clean a Roof & Prevent Algae in Charleston 

Learn how to safely clean your roof, prevent algae streaks, and discover why Atlas shingles with Scotchgard™ technology offer the best algae defense for Charleston homes.

A roof is one of the biggest investments you’ll ever make in your home. It protects your family, adds curb appeal, and plays a huge role in energy efficiency. In Charleston’s humid, coastal climate, one of the most common roofing issues is algae growth — those black streaks that make a roof look older than it really is.

In this guide, we’ll explain:

• How to safely clean your roof

• How to prevent algae from coming back

• Why Atlas shingles are the best choice in Charleston

Why Cleaning Your Roof Matters

Roof stains aren’t just a cosmetic issue. According to the Asphalt Roofing Manufacturers Association, algae such as Gloeocapsa magma feed on the limestone in asphalt shingles, weakening them over time. Moss and lichen make it worse by trapping moisture against the roof surface, which can cause:

• Premature aging of shingles

• Heat retention and higher cooling costs

• Moisture intrusion leading to leaks

• Reduced home value due to poor appearance

Regular roof cleaning and algae prevention can add years to your roof’s lifespan.

How to Clean a Roof the Right Way

1. Safety First

Working on a roof is dangerous. Always use:

• A stable ladder and safety harness

• Non-slip shoes

• Protective gloves and goggles

If you’re not comfortable, it’s best to hire a professional Charleston roofing company like Transform Charleston to perform the work safely.

2. Preparation Before Cleaning

• Protect plants and landscaping by soaking them with water and covering with tarps.

• Clean out gutters to allow chemical runoff to drain properly.

• Pick a cool, overcast day to prevent cleaning solutions from drying too fast.

3. Soft Wash Cleaning Method (Recommended)

Never pressure wash asphalt shingles. Pressure washing strips away protective granules and shortens the life of your roof.

Instead, use the soft wash method:

• Mix a 50/50 solution of water and bleach (sodium hypochlorite).

• Apply gently with a pump sprayer, starting from the bottom and working upward.

• Let sit for 15–20 minutes to kill algae and moss.

• Rinse thoroughly with low-pressure water.

For eco-friendly alternatives, white vinegar or oxygen bleach can also be used, though they may take longer to show results.

4. Stubborn Moss or Lichen

After treatment, use a soft-bristle brush to gently loosen remaining moss. Avoid scraping, which can damage shingles.

5. Final Rinse & Inspection

• Flush out gutters to remove residual solution.

• Inspect shingles for cracks, lifted edges, or damaged flashing.

• Make minor repairs immediately to prevent future leaks.

Need help identifying roof issues? Check out our guide on how to spot a roof leak.

How to Prevent Algae Growth

Cleaning helps temporarily, but prevention is the best long-term solution.

• Trim trees to allow sunlight and reduce moisture.

• Clean gutters regularly to prevent standing water.

• Install copper or zinc strips along the ridge line — rainfall activates them to inhibit algae.

• Ensure attic ventilation to reduce heat and humidity.

• Upgrade to algae-resistant shingles like Atlas Pinnacle® Pristine with Scotchgard™ Protector.

Why Atlas Shingles Are the Best Choice in Charleston

At Transform Charleston, we proudly install Atlas roofing systems, which are engineered for long-term algae resistance.

The Technology Behind Atlas

• Atlas shingles feature 3M Scotchgard™ Protector, embedding at least 10% copper-containing granules per shingle.

• Copper ions are slowly released with each rainfall, stopping algae growth before it starts.

• Most competitors only use 3–5% copper, which wears off quickly — Atlas offers a Lifetime Algae Resistance Warranty.

Why Atlas Outperforms in Charleston’s Climate

Charleston’s humid subtropical climate is a breeding ground for algae. Atlas shingles provide:

1. Lifetime streak-free protection — guaranteed by Scotchgard™.

2. Cost savings — no need for repeat roof cleanings every few years.

3. Enhanced curb appeal — your roof looks newer for longer, boosting property value.

4. Storm-ready durability — with up to 130 mph wind resistance and Class 3 impact protection, perfect for coastal storms.

5. Proven success in coastal markets like Savannah, Myrtle Beach, and Wilmington — areas with conditions nearly identical to Charleston.

Learn more about the difference between Atlas vs GAF shingles in our detailed comparison.

Protect Your Roof for the Long Haul

Regular cleaning helps, but the best way to fight algae in Charleston is prevention. By investing in Atlas shingles with Scotchgard™ Protector, you’re choosing lifetime algae defense, superior performance, and long-lasting beauty for your home.

At Transform Charleston, we specialize in providing maintenance-free roofing systems designed to withstand Charleston’s unique coastal climate. Contact us today to learn more about our roofing services or schedule a free consultation.