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Understanding And Preventing The Unappealing Growth Of Black Algae

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From your home's overall appeal and value to the ability of providing your family with shelter and comfort, the importance of your roof is easy to see. Unfortunately, your roof may develop patches of mold or algae, especially if you live in warm, moist climates. While unappealing, this growth can quickly affect the construction and durability of your roof shingles. Using this guide, you will understand black algae and learn how to prevent this growth from affecting your roof.

 The 411 on Gloeocapsa Magma

Gloeocapsa magma, or black algae, is spread by wind, animals, and other environmental conditions. It develops slowly, accumulating in one spot before spreading out across your roof in streaks. While known as black algae, it is not actually black in color. In most cases, it appears as a dark green color.

As the algae spreads, moisture builds up under the growth. This moisture affects the look and function of your roofing shingles, resulting in warped, loose, or broken shingles. In many cases, this damage to your shingles results in leaks and expensive repairs.


Gloeocapsa Magma can wreak havoc on your roof's look and its underlying function, so preventing this growth is key.

If you need to replace your roofing shingles, opt for algae-resistant shingles. These shingles are treated with a chemical that deters the growth of mold, mildew, lichen, and algae.

If you are not able to replace your roof shingles, consider hiring professional roofing contractors to install metal flashings along the ridge of your roof. As the rain runs off your roof, the copper or zinc metal strips will kill the algae or other growth. This will prevent the growth from affecting your shingles.

Focusing on the landscaping surrounding your home can also prevent the growth and spread of black algae on your roof. Here are a few landscaping tips to consider:

  • Trim Trees – If you have trees around your home, be sure trim branches back from the roof. This will increase the amount of sunlight your roof receives each day.
  • Clean Gutters – Clean out your gutters periodically. Remove straw, mulch, grass, and other debris from your gutters to ensure water is draining off your roof properly.
  • Clean Roof – Remove debris from your roof using a leaf blower or pressure washer regularly. This routine cleaning will prevent algae or mold spores from making your shingles a permanent home. Use a solution containing 2 gallons of water and 2 gallons of white vinegar to wash your roof. The natural antibacterial properties of vinegar will kill black algae and mold without harming your grass, trees, shrubs, or flowers around your house.

Using this information and the help of a professional roofing company, you will understand why black algae develops and learn simple solutions to prevent this streaky growth.