How To Prevent Moss on Your Asphalt Roof

The state of a roof with a lot moss before treating with soft wash roof cleaning detergent in Surrey, BC.

Moss is a single plant organism that normally grows on trees and can find its way in other acidic environments on driveways and grass. Given the right conditions, moss can grow on roof shingles as well. These conditions include limited sunlight throughout the day and a damp environment.

The presence of moss on asphalt roofs causes damage to the property, and can even reduce the lifespan of the roof. Soft washing roofs can eliminate the moss on roofs, as well as prevent the growth of moss in the future.

In addition to moss, other organisms, such as algae and lichen, can grow on the roof. Although these may merely seem unsightly, there are also health concerns that should be addressed.

In this article, we will discuss how to remove moss from asphalt roofs, how to clean the roof properly to remove other organisms, and how to treat the roof to prevent moss in the future.

The Dangers of Moss (And Other Organisms)

As mentioned, moss can wreak havoc on roofs when left untreated. Not only are there dangers to the roof, there are health concerns as well. Here are a few harmful examples of the effects moss, algae, and lichen can cause:

How To Remove Moss From Your Roof

The only way to prevent permanent damage caused by moss is to ensure routine up keep is done to a roof.

For asphalt roofs, the best option to remove the moss, especially for heavily dense moss, it to scrub it off with a tough broom. This is known as bulk moss removal, or ‘debulking.’

Agitating the moss in this fashion will scrub off the majority of moss. But this will not necessarily solve the problem. Simply debulking the moss does reach the root of the moss, and in no time, moss will appear again. This is because the organism is still alive. The solution is cleaning solution. Treat the roof with a roof cleaning solution to destroy the moss at the root and to prevent the growth of moss in the future.

Treat Your Roof To Prevent Moss

After the removal of the bulk moss is complete, it is time to treat the roof to prevent moss growth.

Firstly, this involves making a solution, normally comprised of sodium hypochlorite and surfactant. Ensure proper safety measures are taken be when using these chemicals.

Next, apply the solution on the entire roof, even the areas that were not affected. This is because the spores may have been pushed around during the debulking process, and may have landed on other parts of the roof. The other reason to do this is to create uniformity; the solution acts as a cleaning agent, and will brighten the entire roof.

Note that this process does not involve pressure washing. Applying this solution is usually done with a soft wash, pumping at 90-100 PSI, about the strength of a garden hose.

When the roof is coated, there is no need to rinse it off. Almost immediately, the remaining moss will begin to turn white, and after three to six months, the moss should all be gone and the roof should look like new!

At Revive Washing, we provide roof cleaning services. We do this using our soft washing system to avoid damage to your asphalt shingles. We include a two year guarantee, as well. Call us at 604-398-4040 or get a quote here.

A Video Example of Roof Moss Removal


Our process for treating an 83-unit townhouse complex in Surrey. ##revivewashing ##satisfying ##fyp ##onthejob ##softwashing ##roofcleaning ##mossremoval

♬ Roof – NBSPLV

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