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How To Deal With Green Moss on Roof Shingles

November 24, 2022


Moss growth can create several problems on shingle roofs. While a small layer of thin moss isn’t too troublesome, large clumps of moss can degrade shingles, get beneath them and create opportunities for leaks. Further, many of the methods of removing moss that are recommended online actually damage the shingles, which could significantly increase your odds of getting a leak. So, how do you safely remove moss from a roof? If you plan on replacing the roof, do you need to remove the moss first? And how do you prevent moss from growing back after you have removed it? We’ll answer those questions and tell you other things that you need to know about how to handle the moss on your shingle roof.


How To Remove Moss From a Roof

If your roof has sprouted a moss infection, you can remove it before it becomes serious enough to impact the performance of your roof. Moss is tough and typically you will not be able to remove it by hand. However, you can use a chemical solution to loosen the moss without damaging the shingles. We don’t recommend that you step on the roof for moss removal.

Materials You’ll Need

· A garbage bag.

· A garden hose.

· A ladder (familiarize yourself with ladder safety before you start).

· A moss-specific cleaner that does not use bleach and is rated by the EPA.

· Or your own cleaner mix of mild bleach or mild detergent mixed with water in a spray bottle. You may mix 2 cups of chlorine bleach with 2 gallons of water. Or you can use 8 ounces of dish soap with 2 gallons of water.

How To Remove Moss From a Roof

· Step One: Safely set up your ladder near the moss. With either your homemade cleaner or a store-bought option, spray the moss.

· Step Two: Follow the store-bought cleaner’s instructions for how long you should leave the cleaner on the moss. If using a homemade spray, leave it on for 15-20 minutes.

· Step Three: Using your garden hose on low pressure, rinse the moss thoroughly. You should find that most of the moss will come off from the spray of the water. Be sure not to direct a pressurized spray beneath the shingles or directly against the shingles such that they might lift up. Otherwise, you could create a leak. Even if the moss is not coming off, rinse thoroughly. It is very important to remove all of the cleaner that you sprayed on, or you could damage your shingles.

· Step Four: Any remaining moss should now be loosened enough that you can manually remove it from the shingles. While standing on the ladder, gently lift the moss off the shingles and place it in your garbage bag for disposal. You can secure the garbage bag to your ladder so that you can always have one hand on the ladder.

· Step Five: If some moss is still too ingrained on the roof to be removed by hand, you should not resort to other methods, such as using a brush or a pressure washer, as they may damage the roof. Instead, consult with a professional roofer as to what your next steps should be.


Methods You Shouldn’t Use To Remove Moss From a Roof

Unfortunately, there is a lot of bad advice out there about how to remove moss. While these methods may be effective at removing moss, they may also damage shingles in the process. We don’t recommend you try to remove your moss by:

· Scrubbing: You may be tempted to scrub the moss off the shingles because moss grips shingle quite strongly. However, scrubbing is likely to damage the asphalt shingles and remove their granules.

· Pressure washing: Pressure washers can be very strong and certainly strong enough to break a shingle’s adhesive and lift it up. They also can strip asphalt shingles of their granule surface, which can ruin their performance and destroy their color. Any amount of pressure washing can cause serious problems with the roof, including major leaks. Never use a pressure washer or a pressurized stream of water on your roof.

· Using harsh chemicals: High concentrations of bleach and other chemicals may do permanent damage to the shingles, increasing your risk for leaks.

Using any of these methods may also void your limited warranty on the roof. If you’re in doubt about the safety or effectiveness of a moss removal method you want to try, consult with a professional roofer. A handful of roofers in areas where moss infections are common do specialize in removing moss. They may be able to do the work for you and, if not, may have recommendations about what your specific roof can benefit from.

Hangzhou Singer Building Materials Co., Ltd.
Hangzhou Singer Building Materials Co., Ltd.
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