What Are These Dark Streaks on My Roof?

If you’ve noticed dark streaks on your roof, you’re not alone. These unsightly discolorations, often mistaken for dirt, soot, or tree droppings, are usually caused by algae growth. Specifically, a type of algae called Gloeocapsa magma thrives in warm, humid climates, leaving behind brown or black streaks. In Myrtle Beach, the humid can cause tons of problems for your home, so don’t forget about your roof, too! Understanding what causes these dark streaks, how they affect your roof, and how to address them can help you protect your home and maintain its curb appeal.

What Causes Dark Streaks on Your Roof?

The dark streaks are a result of airborne algae spores settling on your roof. Once it has found your roof, these algae feed on the limestone filler commonly found in asphalt shingles. This growth leads to the discoloration that many homeowners find concerning.

  • Misidentification: These streaks are often mistaken for soot or dirt. However, these sources typically cause only localized discoloration, while algae-related streaks spread more uniformly. They also do not wash off with water.
  • Climate Factors: Algae thrive in warm, humid conditions like that in Myrtle Beach, making them particularly common in the eastern United States. Roofs with northern exposure are more susceptible because they receive less sunlight, which helps algae grow undisturbed.

How Algae Affects Your Roof

While the algae does not harm your roof or your home’s health, it can cause a very unappealing look for the front of your home. Dark streaks can make a home look unkempt, reducing its aesthetic value and possibly impacting its marketability if you’re looking to sell. It is one of the reasons that many homes will have their roof inspected prior to putting it up for sale.

Also, algae can retain moisture on your roof’s surface, which may contribute to shingle deterioration over time. Excess moisture can lead to other issues, such as moss growth or even excess weight on your roof.

How to Remove Algae and Dark Streaks

It is important to note that an solution or cleaning should be done by trained professionals. If you plan to clean your roof on your own, remember that wet surfaces can be slippery, so exercise caution throughout the process. Use proper fall protection equipment and wear personal protective gear, such as slip-resistant footwear and eye protection, to ensure your safety while working on the roof.

1. Gentle Cleaning Solutions

A mixture of water and bleach (50/50 ratio) can effectively remove algae. Spray the solution onto the affected areas and let it sit for about 15–20 minutes before gently rinsing with water. Avoid scrubbing, as this can damage the shingles. This will only work efficiently if the algae is newer growth.

Caution: Bleach can harm surrounding plants, so cover any landscaping near your home and rinse thoroughly afterward.

2. Algae-Resistant Roof Treatments

There are commercially available cleaning solutions specifically designed for removing algae and protecting your roof from future growth. These products are generally less harsh than bleach and can provide longer-lasting results.

3. Professional Cleaning Services

Hiring a professional, such as Carolina Custom Contractors, ensures your roof is cleaned safely and effectively. Professionals use specialized equipment and solutions to remove algae without damaging your roof. They can also inspect your roof for any underlying issues that might need attention.

Tackle Dark Streaks with Carolina Custom Contractors

If the algae growth is extensive, or you’re unsure how to safely clean your roof, it’s best to call in a professional. Carolina Custom Contractors has the expertise and equipment to remove algae without damaging your roof. In addition to cleaning, they can inspect your roof for any damage and provide recommendations for prevention or repairs.

Carolina Custom Construction preserves the health of your home through expert advice and services. We are here to help as your local Pawley’s Island/Georgetown contractors! Whether you need an inspection or are looking to replace your entire roof, our team of professional contractors is ready to help you! Click here for a free consultation so our team can get a better idea of your project!