Cleaning Your Metal Roof
If youve inspected your roof and found no damage, and you feel comfortable getting up on your roof itself, youll need to determine what it is youre cleaning from it, so that you can remove it in a timely way. Keep in mind that most roofs take approximately three hours to clean, and that you may want to test some cleansers on an inconspicuous area of your roof to make sure they dont mark or streak the painted surface before you begin applying them to the entire roof surface.
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 62,781 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.
What If The Moss Appears Dead
If the weather has been consistently dry, moss may appear to be dead. However, some species of moss can stay alive when dried out for months. All it will take is one rain for it to recover and continue growing. If your moss has dried out, take the opportunity to have a roofer remove the moss from the roof.
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Visual Interior Signs Are Evidence Of An Extensive Outbreak
Water intrusion through a roof leak, even a small leak, into the attic and drywall space creates an optimal environment for mold growth. And because these areas are largely enclosed you wont notice youve got a problem until its too late.
Discoloration along the joint between the ceiling and wall is a common indication of having a leak. Youll also find paint around the windows starting to peel or bubble.
Roof mold affects wood in the attic and wood exposed for decorative purposes. Wood gets dark, splotchy, and will often soften.
When To Call A Professional
If the mold covers an area larger than 10 square feet, its best to hire a professional like ServiceMaster.
As mentioned, the above three processes will eradicate light mold. In fact, property owners are encouraged to make efforts to dislodge green mold growth from small areas, such as spaces less than ten square feet. When green mold has overcome a large expanse of ten square feet or more, a professional mold removal and remediation service is necessary to address the problem.
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Rinse The Bleach Solution
After spraying the shingles with the bleach solution, allow the bleach to sit for approximately 15 to 30 minutes, depending on the severity of the mold growth. Using a garden hose at low pressure, rinse the roof shingles thoroughly to remove the bleach solution. When rinsing, start at the top affected shingle and work downwards. While wearing gloves, run your fingers across the shingles. If you still feel slime on the shingles, apply the bleach solution a second time and let it sit for an extra 10 minutes. You can then rinse the roof again.
Easily Remove Roof Mold With Wet & Forget
Wet And Forget is as simple as spraying your outdoor surface and forgetting it. Green algae, black mold, and moss begin to die off on contact. The combination of the wind and the rain breakdown the growth and rinse your surfaces clean over time. Green stains clean up in 1-2 weeks, black stains and moss clean up within a few months. Wet the surface and forget it, there’s no rinsing or scrubbing! Life’s Dirty. Clean Easy.
Wet & Forget Concentrate
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So Is It Roof Mold Or Algae
While algae on a pond often looks green in color, when it is found on a rooftop it frequently appears to be very dark green or black in color. It looks very much like many types of mold, including stachybotrys chartarum, sometimes referred to as black mold or toxic mold. A mold removal professional or even a roofing contractor may be able to offer you a professional opinion as to which one is growing on your roof, but it may be difficult or impossible to know for sure unless you test your roof for mold.
Is it necessary to determine whether you’re dealing with mold or algae? Maybe, maybe not. Many mold removal products will effectively kill and remove both mold and algae. However, it is very difficult to remove mold from some materials, including wood, so special techniques may be needed, depending on the type of roof you have and the extent of the mold growth. We suggest consulting with a roof cleaning professional about whether or not it’s necessary to test your roof to determine whether or not you’re dealing with algae or mold.
Skip Sheathing And Tongue & Groove
For many years the sheathing material of choice was skip sheathing or tongue and groove. Both of these were natural wood products with excellent mold resistance. While mold growth can occur on these materials, it typically requires far more moisture and time for the growth to occur. We regularly encounter attics with skip sheathing that have very poor ventilation and yet, remarkably little mold growth. Part of this is due to the age of the homes and the general lack of air sealing that occurred when they were originally constructed. However, a large factor is simply natural woods resistance to mold growth.
Below is an unusual example of mold attacking the skip sheathing, while the plywood remains largely unaffected. Often this is a sign that the plywood has been replaced recently. The mold growth may have occurred years ago and has yet to attack the new plywood.
White Mold Growth on Attic / Roof Sheathing
Below is a more typical example of mold growth. Note the heavy staining and growth on the plywood. The original skip sheathing has much less growth.
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Why Algae Grows On Roofs
The black streaks, a form of algae known as gloeocapsa magma or roof mold, only appear in the most humid areas of the country. Therefore, its normal for the streaks to appear on the roofs north side. This side of the roof receives the least amount of sun and stays damp the longest.
The bacteria accumulated over time feed on limestone filler and moisture. The algae spores grow and darken, creating the dark streaks visible on roofs. These airborne spores can be carried from roof to roof and infest an entire neighborhood if left untreated.
Not only do the elements and creatures carry the bacteria particles from place to place, the particles foster the growth of other roof inhabitants. The black stains harbor a number of molds or fungi which require warm, humid environments. The fungi lack chlorophyll, giving the them the name of heterotrophs. They feed on organic matter since they cannot manufacture food from raw materials.
On the northern side of an asphalt roof gathers the most moisture, which raises the humidity and provides an abundance of organic nutrients for the fungi to feed off of. Another factor in supplying food sources to the fungi is the tar used in roofing. The substance is ultimately fossilized, dead organic matter.
However, the granule base of asphalt is consumed first along with the tar. The dislodged bases accelerate deterioration of the roof because it cannot prevent the effects of excessive heat or extreme weather.
Are Those Black Stains On The Roof Mold Or Algae
Mold, algae, and moss are very different organisms. Each requires a different method of safe removal and prevention to keep your roof healthy and looking good. Black stains or streaks on the roof will appear anywhere in the U.S., where its hot and humid. In Florida, roof discoloration is a common problem. Most people will refer to these stains as mold, but algae actually cause them.
Whats the difference between mold and algae seen on a roof? Mold is a fungus that eats a variety of nutrients to grow and thrive. In contrast, algae is technically a plant organism that requires all the things other plants need to grownamely, sunlight and moisture. Mold wont form on a roof because its allergic to sunlight, and as soon as the ambient temperature surrounding the mold becomes dry, the mold dies.
Moss, those green, feathery clumps you may see forming on the roof, is a different type of plant and isnt the same thing as algae or mold. Algae is a single-celled organism, while moss is not. Moss also looks like a plant with its tiny stems and leaves. Algae do not have plant-like characteristics. Instead, it spreads out as a clump of single cells and will be slimy to the touch.
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Why Shouldnt I Add A New Roof Over Moss
When you need a new roof, it may be tempting to add a second layer of shingles over your existing shingles. Doubling up your shingles can save time and expense on your roof replacement as your roofer doesnt need to remove and dispose of the old shingles. This strategy is convenient for homeowners because the replacement wont take as long or make as much of a mess. However, there are some circumstances where merely adding a new layer of shingles isnt a good idea.
For example, when you have significant moss growth on your roof, simply covering it up with new shingles isnt wise. Several potential problems may occur if your roofer simply adds a new roof over your existing, moss-covered roof. These potential problems include:
Removing Moss And Other Growth
If you decide to take a DIY approach to clean moss off your roof, you need to take all proper safety precautions. Use a rubber footed safety ladder, and make sure you have someone to spot you. Always wear a helmet, and never walk on the roof of your house. Roofers use a safety harness and rubber-soled boots for traction. They may also install toe boards and roof brackets if necessary. If you cant address the problem from a ladder, you risk a severe injury that will cost a lot more than hiring a professional.
If you can reach the growth from a ladder, you can try following these steps, but be warythere are several ways you can cause damage to your roof in the process.
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What Does The Mold Growth Typically Look Like
Mold growth on the sheathing occurs in either a flat, low profile configuration or a fuzzy, 3 dimensional pattern. The flat, low profile growth can often look like soot or staining. In fact occasionally a home inspector will misidentify the mold growth as soot from a fire. Notice the dark staining in the first picture. This type of mold growth will not smudge or wipe off. The dark discoloration will remain long after the mold has stopped growing.
Below is an image of heavy 3-dimensional mold growth on the sheathing. Beneath the fuzzy growth, areas of staining can be observed as well. This type of attic mold is less common and typically easier to remediate. Because the staining is limited, a thinner layer of encapsulant can be applied.
Option Two: Oxygen Bleach
For those against using straight household bleach, oxygen bleach is another alterative in eliminating algae stains. Oxygen bleach uses hydrogen peroxide versus sodium hypochlorite as an oxidizer. The result comes in liquid or powdered form for an eco-friendlier choice.
Once mixed with water, the power or liquid eliminates all foreign specimens without taking the color out of your shingles. In addition, it doesnt affect the vegetation surrounding your home. Using a pump sprayer, spray the solution on the roof continuously for 10 or 15 minutes. The oxygen bleach attacks the roof algae directly and begins to take the stains away.
After the allotted time, take a scrub brush and lightly scrub the shingles. Apply more solution while you work for a deeper clean and hose off the roof once finished. If needed, repeat the previous steps until the stains are gone.
Other special products for removing algae include:
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Make A Bleach Solution
While wearing protective rubber gloves and a breathing mask, carefully pour ¼-part chlorine bleach into a clean bucket with ¾-part water. Next, put a tablespoon of trisodium phosphate to the bleach solution. Pour the bleach solution into a pump sprayer. Generous spray the moldy roof shingles with the solution.
How To Remove Mold & Mildew From Car Exterior
Walking out to your car and seeing mold growing from is enough to concern anyone.There are 3 types of contaminants that youre likely to see growing on the exterior of your car, these are algae, moss and mold. The first two are pretty easy to remove, whereas the mold can be a little trickier, especially if its Artillery FungusIn this article, Ill tell you everything that you need to know to remove mold from your car exterior as well as how to prevent it from happening again.
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What Is The Best Certified Organic Roof Cleaner
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The best roof cleaner, in my opinion, is non-toxic Stain Solver oxygen bleach. Stain Solver is certified organic and is a powder you mix with hot tap water.
It does a fantastic job of cleaning algae from roofs. Many customers have sent in before and after photos of it working. .
It’s best to apply the Stain Solver solution to a cool roof surface, preferably on an overcast day. If you keep the roof surface wet with the solution for just 20 minutes, and then lightly scrub the roof surface, the algae will come off with no issues.
Severely stained roofs may require multiple applications of the Stain Solver solution. The solution also helps to loosen the grip of the shallow moss roots.
Test For Mold When Seeing Green Indoors
Green molds may be identified by their greenish hue. However, green mold may be difficult to recognize, especially since the green mold may appear as different colors on various surfaces.
Splotches of varying hues of green and green-grey in darkened, damp recesses are a certain indication of green mold. Green mold also commonly grows alongside molds of varying types, like black or pink mold.
Wood is a primary target for mold. Wooden floors, ceiling beams, and walls can host green mold colonies. The dark, confined spaces of kitchen cabinetry supply ample nutrients for green mold to flourish on even food, like bread.
While green mold may be easy to spot if the growth appears tinted green, only a laboratory test can prove if the mold belongs to certain species that produce green mold.
Mold test kits are available in abundant supply, giving property owners the ability to determine if unsightly, musty eyesores parading as fungi are indeed mold. Mold removal and remediation services also provide professional mold inspections.
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How To Clean Algae And Moss From A Roof
Its best to clean your roof on a cloudy day to prevent the removal liquid from evaporating too quickly. Apply this liquid solution with a garden sprayer. When using an Anti-Moss solution let it stand on the surface for about a few hours without rain. Your roof will get clean in the next few weeks.
Dont let a bleach mixture stand on the roof surface longer than 20-30 minutes. Rinse it off with the spray from a garden hose after 30 minutes. Remember don’t use a pressure washer, which can damage the shingles by removing their protective layer of asphalt granules.
If accumulations of algae or moss are heavy, a part of it should wash off the roof surface immediately with the stream from the garden hose. Using a brush or broom with medium-stiff bristles you can attempt brushing off algae and moss, but don’t scrub too hard. You don’t want to brush off the mineral granules from the shingles.
If algae, moss or heavy stains persist on your roof surface after rinsing, let the roof dry, and then spray on the bleach solution again. Again wait for 30 minutes and rinse with a hose. Don’t worry if some staining remains after this second rinse. Exposure to rain and sunlight should wash it off over time.
How To Get Rid Of Roof Algae
Prevention is always the best option for dealing with roof algae. You cannot control whether the wind deposits spores onto your roof, but you can prevent the spores from developing into algae. You must make the roof an unhealthy environment for spores. Increase the amount of sun on your roof by trimming back overhanging branches. Schedule regular roof and gutter maintenance to make sure your roof wicks water away as it should. Consider paying extra for algae-resistant roofing materials if you live in a humid region. You could also treat your shingles or shakes with moisture-resistant chemicals.
If it is too late to prevent algae, treat the problem instead. Do not attempt to remove algae from your roof alone. Trying to DIY roof algae cleaning with solutions such as bleach and water could lead to expensive roof leaks or further moisture getting trapped beneath your shingles. It could also put you at health risk if youre not careful. Furthermore, removing the fungus unprofessionally could damage your shingles stripping them of granules and causing unsightly bald spots. Always trust roof algae repair to the professionals.
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