Roof Shingle

Can You Remove Discolouration in Your Roof Shingles?

There are blue-green algae called gloeocapsa magma can cause dark streaks along roof shingles in humid areas. The spores float through the air and eventually bind themselves to your roof.

If you’ve noticed any discolouration on your roof shingles, it might affect the overall property value of your home. In this guide, we’ll take a look at what causes the discolouration on your roof.

What Causes Discolouration in the Roof?

Roof discolouration is usually caused by algae. The algae are known to grow in humid areas and are usually found in warm climates. The algae are known to grow in humid areas and are usually found in warm climates.

Once the algae attach themselves to the roof, they begin to grow. The algae will eventually cause a dark streak to appear along the roof. 

The metal flashing and joint materials on your roof are made of copper or zinc, which are toxic to most types of algae. As a result, you will not see algae forming in these areas. The reason you may notice streaks in your roof is that trace amounts of this copper and zinc can drip down into the flashing from your roof and prevent the chance of algae growth in those areas.

Is This Discolouration Harmful?

The streaks of discoloration on your roof shingles may make your home look like it’s in disrepair when in reality it’s not. Although the discoloration itself won’t damage your roof, it can lead to an overall deterioration of the roof if left untreated.

People may be less likely to buy your home if they think the roof is old and in bad condition. Getting rid of any dirt or stains on the roof can help make your home more appealing to potential buyers.

How Can You Get Rid of Discolouration?

If you decide to clean your roof, be sure to use a soft-bristled brush and a mild detergent without bleach. You should also avoid power washing your roof as this could damage the shingles.

Granule removal can be an issue because it often requires pressure washing, which can wear down roofing materials and shorten their lifespan. Cleaning is often a temporary solution; it may be better to take preventative measures such as trimming trees around your roof or choosing zinc or copper-coated roofing material.

Can You Prevent Future Roof Discolouration?

It can be difficult to prevent roof discoloration, but there are some things you can do to help. The two most effective methods for managing algae growth on a roof are installing a copper or zinc-coated strip along the ridge or your roof. This strip prevents algae growth by stopping the spores from attaching to the roof.

Copper-infused shingles are a type of shingle that is designed to resist the growth of algae. These shingles contain a copper granule which is infused into the shingle. Many modern shingles sold in this area are infused with 6% copper.


As you can see, there are many reasons why your roof may be discoloured. If you notice any of the signs, it is important to contact a professional roofing contractor to have your roof inspected.

Preserve the value of your roof and your home with Wilderness Roofing. We are commercial roofers in Saskatoon that will easily make your roof look good as new. Get in touch with us today to get started.

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