How do I Remove Roof Mold?

K. Gierok

Removing roof mold from a house is not only important in the prevention of a number of serious health conditions, but also gives an overall better look to the house. While there are a number of ways to remove roof mold, some of the best include using chlorine bleach solutions and copper sulfate solutions. In addition, preventing the growth of roof mold to begin with will eliminate the need to get rid of it.

Copper sulfate, which is often included in solutions to remove roof mold.
Copper sulfate, which is often included in solutions to remove roof mold.

One of the best ways to remove roof mold is to use a chlorine bleach solution. To do this, start by mixing a solution that combines one part bleach with three parts water. Pour the mixture into a hand sprayer, similar to that used for spraying starch onto clothing. Be aware that while this application process can be time-consuming, it is essential to ensure complete saturation. Allow the chlorine bleach solution to remain on the roof for between ten to fifteen minutes, and then rinse with warm water from a garden hose. Finally, examine the roof for remaining mold. If any mold still exists, repeat the process, being sure to rinse the roof after each application of chlorine bleach.

One of the best ways to remove mold from a roof is by using a mixture of bleach and water.
One of the best ways to remove mold from a roof is by using a mixture of bleach and water.

Another way to eliminate roof mold is to use a copper sulfate solution. In this process, a solution should be made that contains one gallon water combined with 12 ounces of copper sulfate. Apply the solution to the roof with a hand sprayer using the same method described with the chlorine solution — and be sure to keep a close eye on the roof. Once the mold turns brown, use a broom with short, sturdy bristles to brush the mold off the roof. Finally, wash any remaining mold off the roof using water from a garden hose.

One last way to remove roof mold is the prevent the formation of the mold to begin with. To do this, start by removing any tree branches that hang over the roof in question, allowing the sun to shine fully on the roof. Mildew and mold thrive in a cool, damp environment, and thus eliminating this environment is essential for their prevention. In addition, consider applying zinc strips under one row of shingles near the center of the roof. When rain comes into contact with zinc, a chemical reaction occurs that inhibits the growth of mold. Finally, consider applying commercial mold-prevention sprays in order to prevent roof mold. For best results, these products should be applied at least once per year.

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Discussion Comments


You can also get attachments for your hose, so you can spray the bleach and water via the garden hose. This is much easier and much quicker.

When doing roof cleaning, the hose should also give you enough power to reach the roof without having to climb on top. Of course this depends on how high the roof is and whether the angle is right so that the water stream from the hose can reach the areas with mold growing on them.


There is one side of my garage that gets hardly any sunlight because of plants and trees growing nearby. At least once a year, I have to spray the garage. I have a sprayer, with a nozzle, a wand and a hose attached to a canister. The nozzle gives me more power than a spray bottle so I don't have to stand on a ladder to reach the high spots. Also, the sprayer holds more water and bleach so I don't have to keep going back for refills.

The solution works really well, as well as any mold removal product you could buy from your local garden center, and it's inexpensive. The bleach is your most costly part of the project.

Once when I bought a farm house, I was faced with the challenge of removing mold from the roof and the sides of the house. The house was surrounded by trees. On one side and on the back of the house, the tree branches grew over the roof. At that time, I had no experience cleaning mold from a house, but I had heard about the bleach solution and decided to give it a try.

I took a small plastic spray bottle that I used for cleaning and filled it with water and a little bleach. Then I went to work spraying every square inch of the house that had mold growing on it. I had to spray most of the areas at least twice and some areas several times, but the mold eventually came off and the house, including the roof, looked great.

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