What Are The Black Streaks On My Roof and How Do I Get Rid of Them?

Gloeocapsa magma is a species of photosynthesizing bacteria. To most of us, it is simply known as algae and that is what you are seeing on your roof when you see black streaks. Algae is unsightly and ruins the aesthetics of your home. But in addition to not looking good, it can create lichens and moss and it feeds on the limestone filler of your asphalt shingle. It survives all kinds of climates. In short, the algae must be treated properly and in a timely fashion in order to prevent irreversible damage to a roof. The following will help you figure out how to get rid of the black streaks on your roof…

Where Do the Black Streaks Come From?

The black streaks running down roofs are actually the hardy algae called Gloeocapsa magma. As the blue-green algae accumulate, they develop a dark, hardened outer coating, which results in the black stains you see. Algae was predominantly in the southern regions of North America and has now moved into the northern part of the United States and Canada because of its ability to survive in a variety of climates and its tendency to travel. When the algae become airborne they travel from roof to roof. So if you see black streaks on a neighbors roof you can probably expect to see it on your roof shortly. It will form first on the northern side of the roof that does not receive direct sunlight.

When Is the First Sign You Need To Pressure Spray Your Roof?

Limestone is economical and makes a durable shingle, but the calcium carbonate in the limestone supports algae growth. In algae-resistant (AR) shingles, zinc or copper granules are mixed in with the colored stone topping. When the shingles get wet, the zinc or copper is released, inhibiting algae growth. Roof cleaning not only maintains a beautiful appearance, it protects your investment by extending the life of the roof. While it is tempting to make roof cleaning a DIY project, it is recommended to hire a professional roof cleaning company. Gloeocapsa magma is invisible to the naked eye and has a mass equivalent of a hydrogen atom. This means that once you can see the black streaks, you aren’t seeing one of two of these organisms but millions.

How the Algae Destroys Your Roof…

Blue-green algae slowly consume the limestone over time. The more dark stains these algae create, the more your roof loses its reflective ability. The roof will absorb more heat from the sun which will radiate to the house, causing higher cooling expenses. When moss and lichens grow on your roof, their roots will burrow between your shingles and weaken the overall structure. The roots absorb water and debris delaying your roof from drying efficiently. Then the algae grow. If you do not take action to treat your roof it can cause, health problems, a rise in your utility bill, and reduced curb appeal.

The Process For a Perfect Roof Treatment

The algae will not go away on its own. It is better to act sooner rather than later. When the time comes to clean your roof or the surrounding area keep the following in mind…

  • You want to use a low pressure wash on your roof so you don’t damage it. High-pressure washers are unnecessary and can loosen, lift or break tiles and shingles.
  • It’s best to use a special pump with a 50-foot reach, enabling you to stay off the roof. This method is much safer, considering that a wet roof is slippery, and the pump can also save tiles, which can break when walked on.
  • Make sure to monitor the run-off from the roof so you guard against chemical damage to your plants, windows, and siding.
  • Use and application that is designed to kill algae and mold. It also sticks to tiles and shingles, leaving a residual algaecide for long-term protection.

Contact us (513.874.4484) for more information!

PSI SquareAbout Pressure Spray, Inc.

Pressure Spray Inc. (PSI) has been serving Greater Cincinnati, Northern Kentucky, and Southeastern Indiana as a distributor of pressure washers, parts cleaners, and chemical cleaners for over 30 years and service more than 3,500 customers.

High Quality Products and Service

At PSI, we value customer relationships and high-quality products and services above all, and believe this is why we continue to be successful today. We pride ourselves in being responsive to our customers’ needs and have operated that way from the very day our company was founded. Our products are built to last, and we are committed to ensuring that every piece of equipment you purchase will continue operating at peak performance for years.

Satisfaction Guaranteed

Our seasoned staff is trained to match your cleaning needs with the most ideal equipment available. Because every cleaning situation is unique, PSI technicians are skilled in combining the right set of products to produce the most optimum cleaning solution for your application. We guarantee your satisfaction with our wide range of industrial quality equipment and exceptional service standards or your money back.