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Should You Remove Moss From Roof

S You Shouldnt Use To Remove Moss From A Roof

How To Remove Roof Moss – And Keep It Away

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 dont recommend you try to remove your moss by:

  • Scrubbing: You may be tempted to scrub the moss off the shingles because moss grips shingles 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 shingles 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 youre 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.

When Should I Remove Moss From My Roof

Roof moss removal is a subject that splits opinions. Does moss damage my roof? Will removing it cause damage? And, when should I remove moss from my roof? These are all questions that we are asked regularly. Heres what we think

Does moss damage my roof?

Moss absorbs and retains water, so if there is a lot of moss on your roof, there is also a lot of moisture. Not ideal for a roof. Moss is ultimately a living organism, which needs something to feed on. If left untreated, your roof tiles will become food as the moss begins to eat away at the surface of them.

A huge will be that it will prevent your gutters from always getting clogged up. Ultimately this will save you money on having to keep getting them unblocked, meaning that your gutters work more efficiently at doing their number one job of protecting your home from rainwater.

Will removing it cause damage?

There are several different methods of roof cleaning, all of which have different benefits and give different finishes and none of which should be undertaken by an amateur. Whilst pressure washing can certainly cause damage if done by the wrong person, on the right type of tiles, carried out by an experienced roof cleaner, it is a very effective method of removing the moss from your roof. We would not recommend the use of bleach on your roof, as although it will kill moss it is very corrosive and will cause damage to any plant life surrounding your home.

When should I remove moss from my roof?

How Do I Clean Moss Off My Roof

If you notice moss in small sections, you should remove it. You can try to do this on your own, however, most homeowners are more comfortable hiring a professional to handle the job.

If you decide to tackle the task on your own, avoid using a power washer. Most people dont have the knowledge or skill to prevent the spray from finding its way under the shingles. If you inadvertently force water beneath your roofs shingles, you could end up doing far more harm than good.

A safer way is to use a mix of 50-50 water and household bleach to kill the moss. The Asphalt Roofing Manufacturers Association recommends letting the mixture sit for 15-20 minutes and then rinsing it with low water pressure. As it dies, the moss will loosen, and itll be easier to rinse or brush away.

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Precautionary Measures In Dealing With Moss From Your Roof

You can prevent moss from growing on your roof tiles. The following will help you do so:

1. Thatch and clean roofs regularly Regular thatching and maintenance of your roof, including cleaning debris such as fallen leaves, will reduce the likelihood of moss growing on your tiles.

2. Be sure to fix any problems with the thatch or mortar Maintaining your thatch properly is the simplest way to avoid moss growing on your roof.

If you have any problems with either of these, fix them promptly or hire a professional if you are unsure how to do so yourself.

3. Use a high-quality roofing paint Its possible to paint your tiles with a special roofing paint that prevents moss from growing on them.

This can be a good alternative to re-thatching your entire roof, especially if youve found problems with the thatch or mortar.

4. Enhance drainage If youve previously had problems with poor drainage on your roof, take steps to correct the situation.

You can do this by adding gutters or checking that the tiles themselves are sloped toward the downspouts at a gentle angle.

5. Keep water off of your roof tiles If you wish to keep water off your roof tiles, there are special roofing paints that protect against moisture damage.

You can also ensure that debris such as leaves and twigs is cleared away from the tiles regularly.

7. Keep roof tiles in good shape Regular maintenance of your roof tiles is key in preventing problems with mosses.

Moss Removal Products And Diy Solutions

How to Remove Moss &  Algae From Your Roof

Some readymade cleaners, like Wet and Forget Liquid Mold Remover , can be mixed and applied per manufacturer’s instructions and left to kill the moss with no rinsing required. Others, like Bio-Advanced Moss and Algae Killer , are available in ready-to-go sprays that hook up to your hose. Be sure to follow the mixing and application recommendations to ensure your safety and protect roof tiles, shingles, and plantings from damage.

You can also make your own moss remover for your roof. These are generally less toxic than their chemical counterparts. Chlorine bleach removes mosses, fungi, and mildew, but it may damage plants, so dilute it before spraying on your roof. A good formula? Mix 1 quart bleach with 1 gallon water and 1/4 cup heavy-duty cleaner like trisodium phosphate. Don’t use ammonia-based cleaners because they create toxic fumes when mixed with bleach.

Or, make a plant-friendlier solution of 1 cup oxygen bleach and 1 gallon of water. Home improvement expert Bob Vila says you can also mix 8 ounces of Dawn dish liquid or 1-1/2 to 3-1/2 cups of white distilled vinegar with 2 gallons of water. Pour solutions into a pump garden-style sprayer choose a backpack-type sprayer , which will be safer to use if you’re climbing and standing on a ladder.

Once you’ve decided on your moss-removing solution, it’s time to get started. Follow these step-by-step instructions to rid your roof of moss and any other debris that’s accumulated atop your house!

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They Weaken The Surface

Moss are living organisms. As such, they require food, water, and air to survive. Finding air and water is a given, but what about the food?

Well, they will eat away at the shingles. Manufacturers use preservatives in shingles that they love to feed on. By doing so, it weakens the integrity of the roof surface.

This is the beginning of the degradation process. Its also the gateway to costing you a lot of money.

The rhizoids that anchor the plant will begin to systematically pull the shingles up off of the roof. Since your first line of defense against water, wind, and other debris is weakened, you will run into a whole host of other problems.

How Moss Ruins A Roof

In general, it is north-facing roof areas that receive little sunlight that are prone to mossespecially when the overall climate is cool and damp. But even in damp climates, roof areas that receive even a little strong sunlight each day may not develop moss. You are most likely to find it on areas of the roof that are shady nearly all the time, such as roof areas beneath heavy tree canopies

Roof moss begins with a thin dusting of green that you may notice only from low angles. This thin layer on the top of the shingles gradually expands and becomes wide, thick, and mat-like. The seams between the shingles and the shingles’ edges also develop moss because they tend to be especially shaded.

As moss thickens, it works its way under the shingles and raises them up. If the shingles are wood, this process can happen at an alarming ratewood’s porous surface is prime real estate for moss growth. Once moss has adhered to wood shingles, it is much harder to remove than from the relatively smoother planes of composite or asphalt shingles.

Once the moss is a thick mat, it becomes a sponge that soaks up and retains all moisture. This stored water quickly works its way under and between shingles and then onto the lower levels of roofing felt and the structural elements of the roof. This eventually leads to rot, and rot leads to further decay of roofing materials. The accelerating cycle can even destroy a roof in a matter of a few months.

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How Much Does It Cost To Remove Moss From My Roof

If you do it yourself, the materials you need to remove moss from your roof are inexpensive.

All you need is a ladder, garden hose, spray bottle, and chlorine bleach. Most homeowners already have those supplies.

If the moss is thick and well established on your roof, like the photo below, you should hire a professional.

The cost depends on the size of your roof, the amount of moss, and the labor rates in your area.

According to, roof cleaning can cost between $250 and $1000, with an average cost of $550.

As a rule of thumb, professionally removing moss will cost about 5% of what it would take to replace your roof altogether.

Need Local Roof Moss Removal Near You

How to remove moss from a roof

Of course, if you live in Seattle, Bellevue, Shoreline, Issaquah, or the surrounding areas, feel free to call us at or contact us with any questions. Were happy to help you find the best option for you and your roof. You can also check out our Evergreen Roof Care page for more information. Evergreen Window Cleaning & Home Maintenance is happy to serve however we can.

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Dont Use Laundry Detergent

Or any cleaner not designed for this purpose. The result will be a wave of suds cascading from the rooftop onto your landscaping, walkways, and drive. As a community in British Columbia found out, the more soap, the more suds. This situation is a hassle to clean up and will wreak havoc on plants and wildlife.

Does A Roof With Moss Need To Be Replaced

If you notice moss or algae on your roof, dont panic. The presence of moss doesnt always mean youre destined for a whole new roof, nor does it mean your home has suffered water or moisture damage.

Moss tends to form in areas where it is shielded from the sun. If sections of your roof are under heavy tree cover, these are prime spots for moss to thrive. And if you live in a damp climate that sees a lot of rain, chances are you will notice telltale signs of algae or moss forming on your roof at some point in your homes lifespan.

The presence of moss doesnt always mean that your roof has sustained damage, especially if you catch it early. Like leaves in your gutters, moss is only a problem if you allow it to grow unchecked.

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How To Remove Moss From An Asphalt Roof

Q: We have a green roof that is not meant to be green. Moss is collecting on one side of the asphalt roof. The roof is otherwise in good shape. What I have learned so far is that the roof should not be power-washed. How should one remove the growth, and who does this type of work? I am not interested in getting on the roof myself.

Falls Church

A: The Asphalt Roofing Manufacturers Association distinguishes between moss, a plant with leaves that can grow into thick clumps, and mold and mildew, which are common names for types of algae that simply discolor the surface. Algae creates ugly black or brown streaks but doesnt damage a roof. Moss which is what shows in the pictures you sent is more worrisome because it can damage asphalt shingles. A thick growth of moss works like a sponge, keeping the roofing damp for long periods, and it can lift edges of shingles, making them vulnerable to blowing off in a windstorm.

To clean either algae or moss, the association recommends putting on protective gear and protecting plants, spraying with a 50-50 mix of household bleach and water, allowing that to sit for at least 15 to 20 minutes and then rinsing with low-pressure water. The bleach will kill the algae or moss, but rinsing wont necessarily leave the roof sparkling clean. Algae will disappear and wash away with subsequent rains, the association advises. Moss will loosen over time and may be removed with a leaf blower.


Will Vinegar Kill Roof Moss

What is the Process of Removing Moss from a Roof?

Yes, vinegar will kill the moss on your roof and is a natural substitute for the bleach and water mixture. The process of removing moss with vinegar is very similar to the process with bleach and water. According to, simply clear your roof of debris, pour distilled white vinegar into a bucket with a few drops of dish soap so it will stick to the moss, spray the mixture on the moss, wait a couple of days for the moss to die, then clear it with a brush or garden hose.

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Inspect Your Roof First

Its a good idea to have a professional roof inspection once or twice a year to keep an eye out for developing problems before they require costly repairs. If you have a sizable patch of moss on your roof, it may have already caused some damage to your roof. In some instances, it may be better to replace your roof than waste time cleaning the moss off. Take the time to check for leaks. You may be able to patch them up by replacing shingles or applying sealant. Check the attic for signs of rotting wood. Depending on the extent of the damage, you might be able to replace it without a total tear-off.

A professional roofer can check for leaks, repair or replace shingles, and reseal or replace any flashing thats compromised. They can also quickly identify structural problems and have all the proper tools and training to safely work on your roof.

If the roof inspection shows that the structure is compromised, its time to replace your roof. You can use preventative measures to keep the moss from coming back on your new roof, which well discuss shortly.

Why Is There Growth On My Roof

Moss and other plant or fungus growth is a very common problem for roofs, even in parts of the country that dont see much rain. Moist, shady places are the ideal spot for moss, lichen, and algae to grow. Typically, this will be a North facing part of your roof that doesnt get much sun. Spores can be spread by wind, birds, and bugs, and when conditions are ripe they will bloom.

Newer asphalt, fiberglass, or slate shingles may have a moss resistant chemical coating on them, but older shingle roofs are commonly invaded by moss or other growth. Even if you know how to clean your shingles regularly, moss can be found hidden in the crevices between them.

When moss is growing on a metal roof, theres a good chance the protective coating on your metal shingles has worn off. Because moss usually grows in areas untouched by the sun, it can retain water and stay damp, which can lead to rust or corrosion.

When youre removing large patches of moss from a metal roof, the best bet is to repaint your roof. A professional roofer has the experience to remove moss and repaint your roof safely, and they are much better at spotting signs of wood rot or leaks under your roof. It can take practice to learn how to find a roof leak and its best to consult a professional before attempting any patchwork on your own.

See our guide on how much is a metal roof.

So how do you get rid of it?

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Is Moss Bad For My Roof

Simply put, moss is harmful to your roof. Moss grows exceptionally well in dark, cool, wet climates. This makes the possibility of moss growing on your roof dependent on the environment in which you live. Even though moss is terrible and can need treatment does not necessarily mean that you need an entirely new roof. Moss does not always indicate damage, especially if you take preventive steps and catch it early.

Why You Should Hire The Professionals

Remove Moss From Roof | DIY | 2 Methods

In the case of gutter cleaning, its a good idea to use a professional service. Many different tools are required to get the job done right without damaging your gutters or roof. Hiring a professional service to clean the gutters and exterior of your home or business is an investment in your propertys curve appeal, your safety , and is just a more convenient route for home maintenance.

Get your home summer-ready with LaborPanes. Have the exterior needs of your home taken care of by licensed, trained experts that can clean your home without damaging it. Get in touch today for a free quote!

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