Even though the home or commercial building roof is above eye-level, it is still visible from a short distance. A roof with unsightly algae or moss stains reduces the curb appeal and salability of the home. Algae infestation can shorten the life of a roof, causing an expensive roof replacement. Using the wrong chemicals or methods of removal can also damage the roof and shorten its life.

Algae Infestation

Algae Infestation

Preventing Algae and Moss Infestation With Maintenance

The best way to solve an algae or moss problem is to prevent it from happening in the first place. This can be accomplished with regular roof maintenance, such as SoftWash pressure washing every year or two depending on the area and weather conditions. The location of the building also makes a difference. If a building is in the open with plenty of sunlight and no trees overhanging it, it will not need washing as often. But, a building in the shade of trees with overhanging branches and in an area with lots of rain may need attention more often.

Building owners can get more information on their roof’s condition and care from local experts. Scraping and scrubbing a roof can damage the shingles. Harsh chemicals can also damage the roof and its shingles. The best solution might be hiring a local exterior maintenance company that uses the SoftWash pressure washing technique. Soft wash experts know how to mix the correct chemicals and use the perfect amount of pressure with the correct tools to remove algae, dirt, and moss without damaging the roof itself.

The home or commercial building will look like it just got a new roof at a fraction of the cost. Once the roof is in good shape again, look for the causes of the algae or moss infestation and remove them. Overhanging branches should be trimmed back away from the roof. Gutters should be cleaned and kept clean. Have the roof soft pressure washed more often so the algae does not have a chance to take hold.

Removing Algae and Moss Yourself

Some building owners want to save money by cleaning the algae and moss off their roofs themselves. They are willing to climb that tall ladder and do the work without professional guidance. It is tempting to attempt to scrape the moss or algae off the roof, but this is not a good idea as it can damage the roof and is a lot of hard labor. The moss or algae will return in a short time, and the process will need to be repeated.

A better solution is to apply a solution of beach and water to the roof and then rinse it off with a hose. The plants and pets below in the yard need to be protected as beach is corrosive. This Old House experts recommend rinsing the plants around the house first, then spray wash the roof with 50% bleach and water solution to kill the algae. They do not recommend using high-pressure washers. Then rinse the roof well.

They also recommend inserting a six-inch-wide strip of zink or copper under the row of shingles nearest the roof peak to discourage algae from returning. Gavanized metal will also work and is less expensive.

Replace the Roof With Shingles Resistant to Algae

When it is time to replace roof shingles in areas more prone to algae and moss damage, choose shingles infused with copper granuals. But, until it is time to replace the roof, the building owner must do what is needed to prevent algae and moss growth. The safest, most-convenient solution is to hire a local exterior cleaning company with the equipment and experience to quickly, effectively, and safely do the job.