How to Clean Algae Off Your Roof

Are you wondering what’s causing those unsightly black stains and streaks on your roof? While it could be dirt or damaged shingles, it’s most often caused by blue-green algae. It’s especially common in warm, humid climates like ours here in Florida. You should contact a roofing company in Jacksonville to assess the condition of your shingles if you suspect algae growth.

How Does Algae Spread?

Algae spreads from one infected rooftop to another via airborne spores. Once they land on a roof, they take root and create a dark coating to protect itself from UV rays. This is what creates the ugly, dark streaks you see on your roof. Algae are primarily found in the Southeast due to our hot, humid climate. They usually grow on the side of the roof that receives the least amount of sunlight.

Cleaning Algae Stains

You don’t necessarily need a new roof when you have stains from algae. The stains and streaks can often be cleaned. Once a roofing company in Jacksonville inspects your roof, they’ll determine if your shingles are still in good condition. Sometimes, the shingles have lost their integrity and need to be replaced. But if you don’t need new shingles, the following mixture for removing algae stains is suggested.

  • 4 gallons of water
  • 1 gallon of bleach
  • 1 cup of TSP (Tri-Sodium Phosphate, or a phosphate-free substitution)

Use a garden sprayer to apply the mixture. Allow it to sit on the roof’s surface for up to 20 minutes. Rinse completely using only low-pressure water. Do not use a pressure washer, as it could dislodge granules and prematurely damage your shingles. Exercise extreme caution as the roof will become very slippery when wet, and should not be walked on. Take care to protect any nearby plants and shrubs that the mixture could harm.

Additional Tips to Prevent Algae

  • Cleaning does not guarantee that unattractive algae stains won’t return. For a more enduring solution, a strip of copper or zinc sheet metal can be installed on the side of the roof. Copper and zinc inhibit the growth of algae.
  • Since algae prefer to grow in moist, shaded areas, keep trees around the house trimmed back. The more the roof is exposed to sunlight, the less chance algae have to spread.

Install Algae Resistant Shingles

If your algae problem is unmanageable or your shingles are old and damaged, a new roof is the best solution. Reliant Roofing installs GAF shingles that are made with granules which are specially formulated to inhibit algae growth. They come in array of color selections and will keep your roof looking like new for years to come.

Named Void Magazine’s Best Roofing Company in Jacksonville, Reliant Roofing is a GAF Master Elite contractor. Contact Reliant Roofing at (904) 657-0880 to find out more.