How to Remove Black Streaks from Asphalt Shingles

How to Remove Black Streaks from Asphalt Shingles

The whole idea is to extend the life of your roof. Although black streaks won’t cause immediate damage, over time, they can cause your roof to age prematurely.

Your roof is meant to keep you and your family protected from the outside elements of weather. When you see black streaks on your shingled roof, it is time to remove them and time to know how to prevent them from returning. There are several reasons why you could have black streaks on your roof. Some of the reasons present a threat to its integrity.

We tell you what you need to know about the care of your asphalt shingled roof.

Reasons for Black Streaks

As a homeowner, you want to keep your home looking in good shape. Knowing what makes your roof dirty is important for knowing how to keep it clean. One of the biggest aspects of roof maintenance is understanding what sort of condition causes a threat to your roof. It is inevitable that your roof will reveal its ongoing battle with the elements it protects you from.

There are all kinds of ways that our homes can suffer the ill effects of weather. This typically results in grime that can build up on your roof shingles, and much of this results in unsightly black streaking.


Black streaks on your roof are most likely due to the presence of algae. Gloeocapsa magma, a blue-green algae, develops a hardened, darker outer coating, which shows the darker outer coating that results in black stains on your asphalt roof. The longer this algae remains on your roof, the longer it feeds on the limestone found in your asphalt shingle roofing. The result is a weaker rotting roof.

Algae on your asphalt shingles will grow worse every year. It will spread, get larger, and more noticeable, trap moisture, and cause premature aging. To prevent your shingles from rotting, you need to remove them right away.

Mould and Mildew

During wetter months, growths like mould, mildew and moss can grow on the surface of your roof. During this time, your roof remains damp, which promotes rot. This cycle then increases the growth of mould, mildew, and moss.

Although not as common, they can also cause black streaks and stains. It is critical that this, too, be cleaned off quickly. The integrity of your roof is at stake. But it is important to remember not to use a high-pressure washer; this can damage an asphalt shingle roof faster than the elements that infest it.


Your roof can also collect dirt and debris from your weather elements. From dust, leaves, and branches to insects, your roof can be a magnet for everything it is protecting you from. Use a safety ladder, heavy traction shoes or boots, and rubber gloves.

If using a tool, be careful. If you use a rake on asphalt shingles, move it from top to bottom to avoid pulling up the shingles. You’d have to replace damaged or missing shingles immediately to avoid severe roof damage.

Removing Black Streaks from Asphalt Shingles

If you notice black streaks on your roof, one of the first things you need to realize is that the work is dangerous. At the same time, you need to remove them expediently. For this reason alone, your need to bring in a professional to handle the job. They’ll have the right safety equipment and experience. The risk of falling is real. And a professional can get the job done faster without doing damage to your asphalt shingles.

Asphalt shingle roofs should not be power washed as it is easy to damage the shingles. A Professional knows how to handle roof cleaning situations to avoid damaging the roof, which would result in expensive repair costs.

The best way to prevent black streaking is to apply a mixture of water, bleach, and trisodium phosphate. Make sure to protect your plants as they can be damaged by the runoff of this mixture. Unless you use a regular and deliberate prevention strategy, the algae and black streaks will return.

West Coast Moss Removal is Your Roof Cleaning Expert

Leave it to us. We’re professionals. West Coast Moss Removal will always be there for you. Whether you need some great advice or our professionally thorough and efficient work. Either way, we can come to take a look at your roof for free, quickly determine its condition, and give you the best advice on how to handle it. Contact West Coast Moss Removal. We’ll evaluate your roof’s situation and give you the best advice. We are your roof cleaning expert.

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