In this guide, you’ll find details on identifying algae growth, causes of algae growth on roofs, problems caused by roof algae, and getting rid of algae on roofs.

Other details discussed include preventive measures and the benefits of calling professionals for algae removal on roofs.

Let’s take a look at each of these points as follows;

Cleaning Algae from Roof

If you live in a warm or humid region, algae growth on roofs can be a common occurrence. This typically results from airborne spores of the blue-green algae, one of the most common algae.

This can be challenging without the correct information on steps to take. Here, we’ve set out to provide helpful tips on how to rid your roof of all algae.

Identifying Algae Growth

Before an intervention is deemed necessary, there needs to be an identification of a problem. In other words, algae growth on your roof must be confirmed.

To identify such growth, you’ll need to look for things like streaks or stains that look like mold. A lot of times, both algae and moss growth may occur on your roof.

These are often (erroneously) used interchangeably.

Thankfully, the methods of removal are typically the same. Differentiating between algae and moss on your roof is easy. You only need to observe the appearance.

Algae crawls or grows flush to your roofs, while moss grows vertically or upright. Besides streaks that signal algae growth, you may also notice clumpy greenery spreading across your roof.

A discoloration of any area of your roof may be a sign of algae growth. Also, affected areas may feel slimy when touched. When left unattended, this condition may result in rapid deterioration of roofs.

Causes of Algae Growth on Roofs

Having identified algae growth on your roof, figuring out its causes is vital. So, what are the common reasons for the appearance of algae on your top?

This condition can be attributed to humidity, moisture, debris accumulation on roofs, and warm climatic conditions within a region. Shades from overhanging trees may also result in algae on roofs.

Roofing materials may also play a role in determining suitability for algae growth. Some roofs are known to have a porous or granulated surface, while others are smooth to the touch.

The former offers a more conducive condition for algae growth than the latter. Asphalt shingles are among the algae-prone roofs you should know of.

There are still others in this category.

Removing Roof Algae Completely

Removing algae growth on your roof involves a range of measures. First, you must choose between doing the job yourself (DIY) or calling the pros.

Most people will choose the latter as it’s more efficient and requires no effort on your part. Let’s briefly discuss each of these approaches as follows;

i. DIY Algae Removal on Roof

As a DIY enthusiast, there are effective ways to go about getting rid of algae on your roof. First, you’ll need the right tools and supplies before getting started.

These include a ladder, algae roof remover, slip-resistant shoes, a pump sprayer, old clothes, rubber gloves, safety ropes, a garden hose with a spray nozzle, and safety goggles.

With these acquired, you’re ready to get the job done. Mix equal parts oxygen bleach cleaner with water. You can also add about half a cup per gallon of trisodium phosphate.

This makes for a more robust cleaner. Spray this onto affected areas of your roof and leave it to sit for half an hour. With this solution, your roof could get slippery, so extra caution is needed.

This solution acts on the algae by killing it. Enough time is needed for best results. With the wait (30 minutes) completed, rinse your roof at low pressure using the hose provided.

Immediate results may not be observed in most cases. This becomes more obvious after a few days when algae are dried up.

ii. Call the Pros for Algae Removal on Roof

Professionally removing algae growth on roofs is one of the most comprehensive ways to deal with the problem.

These are skilled and experienced technicians who understand the problem and know how best to tackle it. Several contractors offer such service, hence the need to strategically choose your service provider.

One way to hire a contractor includes asking the right questions, including their service warranty and liability, and comparing quotes from multiple companies.

Discovering what customers say about the company’s service is essential. Therefore, consider researching customer reviews before contacting the company.

Problems Caused by Algae on Roofs

Algae can cause significant damage to a roof through steady deterioration, which affects its appearance, especially when black streaks or spots emerge.

It rapidly spreads to other structures around the area when the spores travel. With moisture trapped in your roof, a mold problem also results, which can be a health challenge.

Maintenance and repairs may be too late when an algae problem is left for too long, as it affects the integrity of your roofing system. Wood rot is another possibility when algae growth lingers.

Another problem you might have to deal with is a decrease in your home’s value. These issues must be avoided through prompt repairs and scheduled maintenance.

Preventive Measures for Roof Algae

There are preventive measures to consider implementing. These help extend your roof’s lifespan. Start by cutting back overhanging tree branches, which contribute to debris accumulation.

Periodically rid your roof and gutters of debris to limit algae growth. If drain spouts are not correctly laid out, redirect them to reduce the moisture contribution.

When blowing off leaves and debris, have the blower pointed downwards to avoid blowing them underneath the shingles. Monitor your roof for standing water and adjust the area for better drainage.

The Best Roof Types to Contain Algae Growth

If you plan on roofing your building and wish to forestall future algae growth, you’re better off going for roofs made from algae-resistant materials.

Such include composite shingles, copper roofing, and synthetic roofing membranes. There are still more you can research on.

The other alternative is using regular roofing materials like slate, metal roofing, etc., and having them coated or treated with algae-resistant material.

Removing Algae Discolorations on the Roof

After treating your roof of algae growth, you’re likely to be left with discolorations or stains. Getting rid of these can be time-consuming and challenging for the uninitiated.

However, your best bet for getting the job done effectively is having the pros carry out this process. Of course, this will come at a fee.

Handling algae problems on a roof can be achieved by following the above steps. We recommend you seek professional help for the best results.

Benefits of Calling the Pros for Algae Cleaning

Your roof is one of the most vital components of your building and takes up a lot of investment.

Any problems shouldn’t be taken lightly, as they could lead to expensive repairs or even premature roof replacement. You’ll need to call for professional help as quickly as possible to avoid such.

Also, DIY approaches aren’t always as effective as professional treatment.

There are several advantages to calling for algae removal on a roof by a professional. A few of these include having better results and being able to negotiate for scheduled maintenance.

Significant damage caused by algae growth is forestalled as it’s tackled early enough. Also, any other issues not necessarily tied to algae growth are identified.


When algae growth is confirmed on your roof, it remains to be treated or eliminated. You have two options to fix the problem: the DIY approach or calling a professional.

The choice of what step to follow largely depends on your knowledge of the problem. Also, not everyone is comfortable climbing up their roofs, especially without the proper safety gear or equipment.

There are also tools needed to get the job done. Even with every other thing in place, the skill and experience necessary to rid your roof of algae may be deficient.

Faced with these realities, you’re better off calling a professional to do the job. These may include pressure washing services, roof contractors, and algae removal specialists.

If you must get the job done via DIY, the proper steps must be taken. Make an equal parts solution of bleach and water to be sprayed on affected areas.

Bleach is known to kill algae. After spraying, allow to sit for 30 minutes before scrubbing off.

However, this approach is short-lived as it won’t prevent regrowth because algae spores are transported in the wind.

Removal of algae on a roof can be achieved using the tips provided above. It’s essential to take precautionary steps to prevent the problem from worsening.

Speak with a professional about your algae issues today for immediate solutions.

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