Removing Moss Mildew Fungus And Associatedstains On Roofs
Roof cleaning is a topic that draws yawns in New England but causes shudders andscreams of agony from Florida and points south, where vegetable life seeksworld domination! How do we keep that “fungus among us” under control.
Since starting on a quest for the ideal method of cleaning fungus and algaefrom roofs, I have contacted dozens of individuals and companies. Some of my readers came forwardwith suggestions and a few companies also supplied information helpful to thisresearch.
For the purposes of this article, the terms “mildew”, “fungus”, “algae” and”moss” are interchangeable… even though their mothers’ might object!
How To Prevent Moss On Roof
Happily, there are preventive measures you can use to keep your roof moss-free. First, let the sunshine in! Trim branches overhanging your roof, keep gutters free of debris, and regularly remove moisture collectors, such as leaves, branches, and seedpods, that pile up on the roof and encourage moss to grow. The best long-term solution? Attach strips of zinc or zinc-coated metal flashing strips just below a roof’s peak or ridge caps. When it rains, water flows over the metal strips leaching out moss-retardant zinc particles, which attach to roof shingles and/or tiles to stop new moss from forming.
Working safe, smart, and strategically guarantees your moss-removal operations will run smoothly. These prevention measures mean you’ll be able to stay off the ladder and roof for seasons, if not years, to come.
How To Clean Roof Shingles From The Ground
If you are concerned about voiding the warranty on your roof shingles due to walking on them, then you can clean your shingles from the ground. In this instance, using a garden sprayer attachment with your hose is ideal. Put liquid bleach in the sprayer and apply from the ground. Apply bleach from top to bottom, as you dont want to spray up and under the shingles.
It is important to note that leaving the bleach on the roof to sit too long will damage the roof. Ensure that you rinse the roof after 15 or 20 minutes. Repeat if necessary until all the damage is gone.
Best Time to Clean an Asphalt Shingles Roof
The best time to clean a shingle roof is when there is no rain in the forecast for several days and when temperatures will not drop below freezing. Freezing will freeze water to your roofs surface, negating the effects of the cleaner.
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How To Clean Roof Algae
The easiest way to clean algae off roofs is with the use of bleach and water. As long as the problem has not advanced to the point where the roof is seriously compromised, a 50/50 mix of bleach and water should clear away the algae and restore the cleanliness of your shakes or shingles. Bleach is the active ingredient that kills algae on contact.
After mixing bleach and water in a large plastic bucket, gradually spread the mixture over your roof with a mop. The algae should quickly loosen up and wipe away from the shingles as you cover the roof, foot by foot. Once you have finished, hose the mixture off the roof. This stage is a good time to check your gutters for any obstructions that could possibly impede the drainage process.
To prevent the re-growth of algae, line the shingles with copper flashing to inhibit any further development of algae, which is allergic to copper. Better yet, contact a roofing service professional to perform this service. A licensed roof cleaner will know how to keep balance and perform the job fast on a residential rooftop.
How To Remove Moss From Your Roof
Roof going way too green? Use these materials, tools, and methods to eradicate moss from your rooftop.
Greenery overhead should be limited to leaves flushing out tree canopies. If mossy foliage covers your roof, it’s time to get cleaning. Moss grows in areas untouched by sun, so it can develop at a speedy pace on tree-shaded and north-facing roofs. Spreading moss can quickly upholster to roof surfaces, filling in voids between shingles and tiles and reaching under and lifting up roofing materials. This heaving of shingles allows rainwater and other moisture to seep into a roof’s structure to cause decay and rot.
Before you clean moss off a roof, you’ll need to consider how you want to kill the plants and remove the dead layers of moss. After cleaning, you’ll also need to put some defensive measures into play to prevent roof moss from growing back.
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Can I Clean My Roof Myself
Yes, but its dangerous if you dont know what youre doing. A basic bleach formula is:
- 1 quart bleach
- 1 gallon water
- 1/4 cup TSP or other heavy duty cleaner
Do NOT use a cleaner that contains ammonia or is not recommended for mixing with bleach. It can result in chlorine gas, which is poisonous. If you are unaware of why you shouldnt mix bleach and ammonia, skim this article. This mixture may hurt your vegetation nearby, so be careful when using it. A professional roof cleaning company uses a mixture of chemicals that can be eco-friendly.
After you have your solution into a sprayer and you begin spraying your roof, itll become wet. Wet algae can be slippery, even more so than just a wet roof. If you plan to clean your roof by yourself, take extra safety precaution throughout the entire process.
Professional roof cleaners can tell you from the beginning, before any unnecessary work, if your roof needs to be replaced. And if thats not the case they can get your roof cleaned and back to a brand new state, free of algae and any other growth issues. The important thing to remember is to keep an eye on your roof and get regular cleanings to prevent bigger problems from arising. Once its there it can be taken care of, but why let it happen in the first place.
Let The Pros Do Their Job
Set a schedule to have your home professionally inspected for roof damage at least annually twice a year is ideal. Scheduling an inspection before the start of a severe weather season is a great way to catch issues like loose shingles or failing flashing before they become a major problem. Having your roof inspected after a major storm is just as important, plus post-storm repairs may be covered by your homeowners insurance.
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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 dont recommend that you step on the roof for moss removal.
Materials Youll Need
- A ladder .
- 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
Preventing Reinfestation Zinc Strips Are One Option
If you wish to prevent reoccurrence of fungus, think zinc! Zinc strips have been used for many years as an algae preventative. StainHandler.com offers sets of 3′ zinc strips, which areattached near the peak of the roof. When it rains, a slight amount of zincdissolves from the strips and coats the roof, inhibiting algae and fungusgrowth.
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Washing Powder To Kill Moss
A widely believed approach is that sprinkling common washing detergent powder across the moss will kill it. Then, you can just spray or scrub the dead moss off the shingles to save on expensive professional services.
Experts from Roof Life of Oregon confirm that it is technically true that commonly available detergent will kill moss. In addition, they say, you can physically remove the treated dead moss by spraying it with a high-pressure hose or scrubbing and scraping, although this method is more complicated and expensive than it seems. It takes a surprising amount of detergent to kill moss.
In addition, the cost of a pressure washer or other high-pressure hose adds to the expense of such a project. Furthermore, misuse of such a powerful stream of water can lead to roof damage that would be quite costly to repair.
Whats The Safest Way To Clean Algae And Moss From Asphalt Shingle Roofs
You might think that taking a power washer to the roof is the quickest and most effective way to remove algae and moss from the shingles. But power washers are too strong for the shingle granules and will wear them down. Asphalt shingles are designed to withstand rain, not the force of a power washer. Power washing your roof will reduce its lifespan.
Instead, gently pray the roof down with a mix of half bleach and half water. Let the mixture sit on the roof for 20 minutes before you rinse it off. But be sure to wet your plants around the foundation down with water first. This will protect them from the bleach mixture run-off. Then, rinse your foundation plants down with clean water again, so they arent damaged.
Rinsing the roof after bleaching it wont make it look pristine. Your roof will actually look a bit worse before it gets better. The algae will slowly disappear with each rainfall after you bleach it. Moss, however, will look yellow right after bleaching. Gradually, it will loosen from the roof shingles. Once it does, then you can safely remove it with a leaf blower. It can take several weeks to several months for the moss to pull away from the shingles.
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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.
Chantilly
Mold And Mildew Growth
As you can see, the alga gets on your roof easily enough the wind just has to blow in the right direction and there it is. Just as easily, mold and mildew follow. The standing water and humidity, the rapidly growing spores and wood rot, these are quick and fertile breeding places for mold. This can be expansive, and as a result, expensive. Often the damage is done well before its discovered, as mold on the outside of the house is usually indicative of mold on the inside of the house.
You cant prevent spores of algae and moss or mildew from landing on your roof. But you can prevent growth. Obviously the best care is preventative care. With regular cleanings you can get rid of the algae before it even becomes an issue, and definitely before it gives way to rot, mold and mildew.
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How To Stop Roof Fungus
The spores of algae, moss, mold and mildew travel through the air, but they dont nest on rooftops unless certain conditions are in place. For example, if a house is situated in a clean and dry environment, none of the growths are likely to occur. Likewise, a house with sufficient roof drainage is more likely to avoid the problem. That said, the most effective way to prevent the problem is with biannual inspections of your roof.
On houses that are highly vulnerable to rooftop formations of algae, moss, mold and mildew, the problem can also spread indoors if gaps exist where standing water can leak into the attic. If a fungus has developed along moisture deposits and water puddles on the roof, any path that leads indoors will carry the malignant growth into your home.
With biannual professional inspections, you can identify such problems before they impact the structural integrity of your roof and the sanitation of your house. That said, there are steps that you can take as a homeowner to reduce the chance that fungus spores will develop into harmful growths on your rooftop. Perform the following steps each spring and fall to help keep your rooftop free of algae, moss, mold and mildew:
Along with biannual roof inspections, the above-listed steps can help drastically reduce the possibility of harmful growths on your roof and extend the overall life of your roof.
Problems With Using Bleach On Asphalt Roofs
There is some concern regarding the use of chlorine-based productson asphalt roofs. Household bleach can damage asphaltdue to its high sodium content. Apparently, the sodium causes anelectrochemical reaction that reduces the elasticity of the asphalt leading to stiffness, brittleness and curling of the shingles.
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What If The Moss Grows Back
If the moss does return, do not rely on harsh chemical treatments or dry spells to kill it. Chemical treatments may harm shingles as well as moss, creating a more significant problem. Dead moss must still be removed by hand, or it will impede the flow of water off the roof and create issues. It may cause standing water. It may also clog gutters or allow for leaks.
How To Clean Mold Off A Roof
This article was co-authored by Mike Kapur. Mike Kapur is a home inspector and the owner of Sonic Home Inspections, a home inspection company in Westchester, New York. With over 15 years of experience in pre-inspecting properties, Mike specializes in mold, radon, asbestos, lead, water, and air quality testing as well as hazardous materials, pest, infrared, and general home inspections. Prior to founding Sonic Home Inspections, Mike worked pre-inspecting apartments. Mike holds a BS in Accounting from Queens College and is a Certified Mold Assessor in the state of New York.There are 17 references cited in this article, which can be found at the bottom of the page. This article has been viewed 63,879 times.
Its easy to let a mold problem sneak up on you on in out-of-the-way places like the roof of your home. Just because you cant see it, however, doesnt make it any less dangerous. At best, slimy black mold deposits are an eyesore at worst they can pose serious health risks. Thats why if you find evidence of mold growing on the roof of your home, eliminating it right away should be a high priority. You can bust up stubborn mold, along with other types of growth like moss and algae, by spraying your roof down with a powerful chemical cleaner.
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Roof Moss Removal: Cleaning Mold Algae & Moss From Your Roof
We don’t recommend trying to handle roof algae and moss removal on your own. We recommend hiring a professional.
If you are a DIY person capable of climbing a ladder and not afraid of heights, you may be able to tackle algae or moss removal yourself.
The safest method for your roof and the environment is to use a product called Spray and Forget or Wet and Forget. These products can be purchased at most local hardware stores, can be put into a hose-end sprayer, and applied in many cases from the ground or a ladder or the edge of the gutter. These methods can take 3-6 months to work but are the safest. Take some time to research these products before use.
Another more aggressive method for quicker results is the use of water and bleach. Below are the general steps for this method:
- Mix 1 part oxygen bleach cleaner with 1 part water.
- Pour the bucket of solution onto the affected area of the roof and let it soak for 30 minutes.
- For larger sections affected by algae or moss you could put this solution into a spray pump and apply. Be extremely careful not to step on wet algae or moss as it is very slippery and could cause a slip and fall!
- After 30 minutes, rinse the mixture off with your hose on a low-pressure setting. NEVER PRESSURE WASH YOUR ROOF. The moss won’t come off your roof immediately, but within a few days, it will dry up and blow off with the wind. If your roof is pretty well-covered in moss, you might need to use a leaf blower to get rid of the remains.
