How to Safely Remove Algae From Your Roof

The presence of algae on your roof is both unattractive and costly. If you don’t take action quickly, algae can cause a great deal of damage to your roof and home. 

The best way to safely and effectively remove algae from your roof is to hire a professional to perform a roof treatment. While it may seem like you can do it yourself, roof treatments require special equipment and cleansers. And it is dangerous to reach second story roofts. In the end, calling a professional is a more sensible and cost-effective decision.

What Is Algae?

Gloeocapsa magma is the scientific term for the algae on your roof. Algae generally appears on the north side of your home. One reason for this is that the north side of your home gets less sunlight than the other sides. Algae and mold form more easily in darker conditions and moisture. If untreated, additional dirt can make its way to your siding that algae can feed on, causing it to widen its coverage.

Algae is most common in areas that have a cool and moist climate. Because of the climate in the Midwest, these roofs hold moisture longer and create a breeding ground for algae. Algae colonize where there is a lack of direct sunlight. While it is most commonly found on shingles, algae can also be seen on siding and other areas of a home’s exterior.

How To Remove Algae 

Do It Yourself

Bleach can neutralize and kill algae off your roof and remove the black streaking. However, this comes with risks. Bleach is corrosive and dangerous to plants and pets. It must be diluted before applied and plants must be rinsed down. Also, your home needs a proper place to drain chemicals. Due to the number of risks at play, we do not recommend attempting to treat a roof yourself.

Hire A Professional

Hiring an insured professional will protect you against any harm caused to your roof or the worker.

Second, it is likely there are more living organisms on your roof than just algae. Gloeocapsa magma has a symbiotic relationship with certain fungi that leads to the growth of lichens. A professional will check and treat for more than just algae. 

Lastly, a professional will be certified. They will have access to the right chemicals and your roof treatment will come with a warranty.


Hiring a professional like K&T Windows to remove algae from your roof is an easy decision. It will save you time, money, and ensure your roof is being treated safely and effectively.