What You Should Know About Moss Growth and Asphalt Shingles

If you have an asphalt roof and want to keep it looking great and working well, check out these facts you should know about moss growth and asphalt shingles.

Moss Loves Moisture, Humidity, and Darkness

Moss is common in rainy environments because it loves moisture, but it also loves humidity, and many roofs are humid because of heat escaping the house, sunlight hitting the roof, and so forth.

If you live in an area with lots of shade from trees and buildings, the moss can thrive even more. Having a lot of tree limbs hanging over your roof also increases the risk of leaves and other organic debris, which feeds moss. While you may not be able to reduce the moisture or humidity on your roof, you can keep it clean from debris.

Moss Keeps the Roof Wet

Moss isn’t just attracted to moisture; it helps keep your roof wet by storing moisture and preventing proper drainage. This lack of drainage not only helps the moss grow and thrive but also may damage your roof because it increases the risk of water getting under the shingles.

Once under the shingles, the moisture can reach the underlying structure. This moisture increases the weight of the roof, which increases the risk of collapse, decay, leaks, and water damage inside the home.

The Moisture Can Freeze

If you live in an area with freezing temperatures in the winter, extra moisture on your roof can cause major damage. When the water freezes, it expands, so if water has gotten under the shingles, the expanding ice may cause more damage, allowing more water to penetrate.

If you aren’t keeping your roof clean from moss, then dead moss may get trapped in the gutters, causing them to clog. Clogs cause water to overflow, pooling around your foundation, but they also increase the risk of water and ice being pushed under shingles because the gutters are too full.

You Can Remove Moss From Healthy Roofs

If your roof is in good condition, you can remove the moss with moss killer, bleach, and a brush without damaging the roof. However, you may be better off hiring a professional, especially if the shingles are showing signs of wear and tear.

Walking on a damaged roof and cleaning moss from damaged shingles can cause more problems. You may tear shingles, remove too much of the aggregate, or cause other issues that may result in expensive roof repair. Similarly, if your roof is severely damaged, you may need a new roof rather than moss removal.

There May Be Residual Stains

Moss doesn’t tend to leave residual stains after removal, but if your roof is prone to moss, it is likely prone to algae too, which does leave a stain. After the algae is removed, it may affect the overall aesthetics of your roof and home. The best way to remove these stains is to hire a professional who can chemically clean the roof safely and effectively.

If you have an asphalt shingle roof and are tired of seeing moss year after year, do something about it. A professional roof cleaning from our caring staff will keep your roof looking great and protecting your family. For more information about how we can help you, contact Roof Doctor today.

Comments (1)

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    Johnny McCarron


    I’m glad to know that you can remove moss with some moss killer and a brush. My parents noticed some moss growing on their roof last week. I’m going to recommend that they purchase the necessary equipment, including a long-handle bitumen brush, to get rid of it.


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