Roof Cleaning in 2021? Helpful Blog

The term Roof Cleaning brings up several common questions for someone just learning about it for the first time. Why should I clean my roof? How to clean roof shingles? What types of roof cleaning products are available? Can I do it myself or do I need to hire someone? How much does it cost?

There are several different reasons why someone may decide to clean their roof. The most common reason is to restore the appearance of the roof as well as the overall curb appeal of the home. Whether its black streaks on the roof due to the growth of air-borne algae known as Gloeocapsa magma, mold, mildew, roof moss, or lichen, exterior blemishes make a great house look neglected and unsightly. When selling your home it is especially important in order to maximize the value of your home and to eliminate any perception to potential buyers that the roof would need to be replaced if they decide to purchase. It could be the difference between selling your home or not.

The most important reason someone should clean roof shingles is to prevent any further damage and premature replacement. Did you know that almost one out of every three roofs are replaced early because the homeowner was unaware that the roof could be cleaned, or neglected to clean the roof and the roof algae, mold, mildew, roof moss, or lichen damaged the roof beyond repair? Not only is replacing your roof one of the most expensive home improvement projects, it’s just not necessary in most cases.

If you still have several years left on the service life of your roof and it’s showing any signs of roof algae, mold, mildew, roof moss, or lichen then you could definitely benefit from roof cleaning. Not only would you avoid spending thousands to replace it, but it will restore the health and appearance of your roof as well, allowing you roof to reach its estimated service life. You wouldn’t replace your vinyl siding due to algae, mold, and mildew stains would you? Absolutely not, you would clean it or have someone else clean it for you. Then why spend thousands of dollars replacing a roof that can be cleaned for a small fraction of the cost?

As you may expect there are several different ways that a roof can be cleaned as well as a variety of roof cleaning products or chemicals on the market today. How someone goes about cleaning a roof is normally directly tied to the roof cleaning product or chemicals that they are using. Deciding how you will clean your roof is really about what you are most comfortable with.

First, you have the Chlorine Bleach or lye (sodium hydroxide) no pressure method. The reason there is no pressure needed is that Chlorine Bleach (sodium hypochlorite) or lye (sodium hydroxide) are very harsh, dangerous chemicals. The part they commonly don’t tell you is that using this method could potentially stain, dry out or damage your shingles, remove the finish on aluminum gutters, stain painted surfaces, damage plants, and grass, or create health hazards for your pets and children. Just a little bit of overspray while cleaning could be disastrous in so many ways, it’s just not worth it.

Second, is the biodegradable and safe method of roof cleaning. This is normally achieved by using a biodegradable and safe roof cleaning product that is hydrogen peroxide-based. This type of roof cleaner takes the worry out of overspray and will not harm the finish on aluminum gutters, stain painted surfaces, damage plants and grass, or create health hazards for your pets and children. Your roof can be cleaned two different ways when using this type of roof cleaner. You can spray it on and then use a pressure washer on a low pressure setting (as much as a hard rain) for instant results or you can spray it on and let the rain rinse away the stains naturally over approximately 90 days.

In my opinion there is really only one choice when it comes to choosing a roof cleaning product. Take the worry out of it; use a biodegradable and safe roof cleaning product. There is absolutely no reason to take the risk of using a harsh caustic chemical like Chlorine Bleach or lye (sodium hydroxide) when there is a biodegradable and safe way of accomplishing the same result.

Lastly, should you clean your own roof or hire a professional roof cleaner? Roof cleaning can be done by a homeowner, a contractor, local handyman, or by a professional roof cleaner. It really depends on your level of comfort being on or around your roof. Having someone else clean your roof will normally cost approximately $500 to $1500 depending on the square footage of your roof. As always, we recommend that you follow all roof cleaning safety practices whether you are a homeowner or a professional roof cleaner and ensure that a biodegradable roof cleaning product is used in order to keep you, your family, and your property safe.


Roof cleaning is a very confusing topic for most homeowners. Ask ten different roof cleaning companies and get ten different answers as to what is the best way to solve your roof’s moss removal problem. You may ask your self, “It can’t be that complicated?” Fortunately, it is not.

Why so many varying opinions?

First, it is important to review why there are so many varying opinions as to what roof cleaning methods and what roof treatments are best. Ultimately, it gets down to access and capital. Most roof cleaning is done by small businesses. In general, this is a very good thing. Small businesses are the backbone of our economy. Customers are usually in closer contact with people who run the business and make the decisions.

But there is also a downside. The smaller of the small roof maintenance companies don’t always possess the capital to outfit with all the equipment to do a job the right way. For many, an investment of $1,000 to $10,000 for a power washer is all they can afford. After making an investment in a specific type of equipment that allows you to clean roofs only a particular way, the pressure to insist that this method is the best is pretty high.

However, there is more to this than just a lack of capital. After all, some methods don’t require too much additional equipment. But they do require access to proprietary roof treatments that the vast majority of roof cleaning companies can not access. Without access to these treatments, they can not offer the cleaning methods that require them. In a sense, it is still related to capital because these companies are generally not able to invest the tens of thousands of dollars to have custom treatments developed.

Conversely, common roof treatments such as zinc sulfate and bleach can be easily accessed. While these specific treatments at times may actually be part of the most appropriate cleaning solution, they simply are not appropriate for many roof’s specific needs.

Additionally, the pesticide licensing required in many states adds an educational requirement to roof treating. To remove roof moss, often a licensed pesticide is required. Don’t be scared off by the word pesticide – some are common (the above-mentioned zinc sulfate) and others are fairly benign and gentle (sodium percarbonate.) But is testing is required, this adds another wrinkle to the equation.

Basically, much of the issue of varying opinions gets down to the reality that many roof cleaning contractors offer the only options that they are able to provide, whether or not they are what is best for the roof.

Education and familiarity

We go with what we know. That is a common axiom for many aspects of life. Roof cleaning is no different. Many companies are founded by those who were previous foremen at other companies. When faced with presenting a service option, they offer what their previous employer offered. I call it the positive momentum of incorrect information. It just keeps getting perpetuated.

Additionally, when someone is working long hours doing hard work, they just do not have much time to put towards industry and professional education. Simply put, many roof cleaning contractors honestly do not know that there are better methods and treatments available.

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