Black Algae Plaguing Your Roof? 2 Options For Removal Using Common Household Ingredients

Living in a warm, moist climate has its advantages and disadvantages. While the warmer weather may be appealing, the humidity can wreak havoc on your home. In many cases, homes in these humid climates develop a dark green or black growth on their roof. Gloecapsa Magma, or black algae, can spread quickly across your roof, resulting in dark, black-like streaks across your shingles. Obviously, these streaks affect the look of your home, but it can also warp, loosen, and break your shingles. This damage can lead to leaks, water damage, and expensive repairs. Fortunately, removal of black algae is possible using one or more of these common household ingredients.

Hydrogen Peroxide

Search your bathroom or medicine cabinet for a bottle of hydrogen peroxide. This common ingredient is great for sanitizing cuts and scrapes, but its antibacterial properties make it an effective algae killer.

In an outdoor pump sprayer, combine 3 gallons of warm water with 3 cups of hydrogen peroxide. Be sure to shake the container to mix the ingredients thoroughly.

To ensure that you remain safe while cleaning your roof, wear waterproof shoes with rubber soles that grip your damp or sloped roof. Ask a friend or family member to hold your ladder while you climb up on your roof.

Use a broom to sweep off dirt, leaves, pine straw, and other debris. Then, pump the handle of your container to create pressure in the sprayer. Spray a generous amount of the hydrogen peroxide solution onto streaked areas of your shingles. Allow it to soak for a few minutes before rinsing with your garden hose.


Creating a vinegar solution at home is an effective option for removing dirt and debris from your roof, but it can also kill the unappealing streaks from black algae. White vinegar contains numerous acidic properties that kill black algae, mold, e-coli, and salmonella without harming the landscaping around your home or affecting your health. To use this natural algae-removal on your roof, add the following to a sprayer:

  • 2 gallons of warm water
  • 2 gallons of white vinegar

Mix thoroughly before spraying a generous amount onto your roofing shingles. Allow the vinegar solution to soak for a few minutes before rinsing with your garden hose.

For stubborn areas of algae, spray the solution on the streaks and scrub with a soft-bristled sponge.

Black algae may be plaguing your roof, but removal is possible. Using these common household ingredients and a bit of effort, you can rid your roof of this harmful, unappealing growth.

For more information, contact Drey Roofing or a similar company.

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Tracking Down Roofing Problems

A few years ago, our roof started to have all kinds of problems. The shingles were perpetually blowing off, and I could tell that there were some underlying rot issues. We could see mold and moss from street level, and so I called in the professionals. Our professional roofing team took the time to get up on the roof, inspect the damage, and recommend repairs. They were incredibly easy to work with, and I was really impressed by their professionalism. This blog is all about things to look for when it comes to your roof and tips for finding an incredible roofer.