Tuesday, June 18, 2024

How To Get Mold Off Your Roof

Dos And Donts: The Best And Worst Ways To Clean A Roof

How to Remove Moss & Mold from your Roof Shingles with Wet & Forget Roof Shingle Demo Video

If youre reading this, chances are youre looking for roof-cleaning tips because your shingles are no longer looking new and attractive. If your roof appears dark and discolored in some areas, you may think that mold has developed on the surfaces of the shingles. However, the black streaks youre seeing are really colonies of blue-green algae. If youre noticing thick, green patches on your roof instead, then youve got a moss problem, The north, west, and shady areas of your roof are most susceptible to these moisture-loving nuisances.

Moss and algae spores are carried by the wind or animals from rooftop to rooftop, which is why entire neighborhoods are often affected. Moss can seriously impact asphalt shingle performance by causing them to curl up and blow off, eventually resulting in leaks. While algae doesnt actually harm your roof, it can impact its aesthetic appeal. Further, climbing on your roof frequently to clean off growth CAN damage your roof and shorten its lifespan by loosening the granules on your shingles. So, its best to know how to clean your roof properly so that you ensure you dont have to do it too often.

Knowing this, what are the best ways to clean a roof of algae and moss growth? Read on for our best roof-cleaning tips!

Clean Out Your Rain Gutters

Rain gutters should be cleaned out about twice a year or as needed, depending on how much debris they tend to accumulate. Trimming or removing trees should help, but leaves and debris can still get stuck on the roof or in the gutters, causing them to become clogged. If the gutters are clogged and overflow onto the lower roofs or stop draining altogether, this would be good news for the moss and bad news for your roof. Fortunately, you can prevent that from happening by staying on top of your regular gutter cleanings. Also remember to check your downspouts and make sure they drain at a safe distance from the house. You can either contact gutter cleaning professionals or grab a ladder and do it yourself.

Roof Mold By Any Other Name

A lot of the dark streaky stuff found on roofs in wet climates like Seattle is actually algae. You probably don’t care to know the difference, and neither does the roofing industry, as most cleaning solutions and other products for roofs are targeted at mold, mildew, lichen, moss, slime, or algae it all works the same. But for the record, algae commonly feeds on the limestone powder in asphalt shingles, while mold often thrives on plant and other organic matter that’s fallen onto your roof. You can’t do anything to prevent algae and mold spores from flying through the air and landing on your roof, but you can help prevent mold growth by keeping the shingles free of organic matter.

Read Also: How To Remove Black Mold From Bathroom Ceiling

Stop Roof Algae From Coming Back

To keep the algae from coming back, insert 6-inch-wide strips of zinc or copper under the row of shingling closest to the roof peak, leaving an inch or two of the lower edge exposed to the weather. That way whenever it rains, some of the metal molecules will wash down the roof and kill any algae trying to regain a foothold on your shingles.

You can probably see this same principle working on roofs in your neighborhood. Look for chimneys with copper flashing the areas directly below the flashing will be free of any algae stains.

The strips also work on roofs suffering from moss buildup. Just scrub it off first with a brush, then bleach as above.

Need help with home maintenance? Read our reviews on home warranty providers.

How Do I Remove Roof Mold

Roof cleaning and maintenance tips

Removing roof mold from a house is not only important in the prevention of a number of serious health conditions, but also gives an overall better look to the house. While there are a number of ways to remove roof mold, some of the best include using chlorine bleach solutions and copper sulfate solutions. In addition, preventing the growth of roof mold to begin with will eliminate the need to get rid of it.

One of the best ways to remove roof mold is to use a chlorine bleach solution. To do this, start by mixing a solution that combines one part bleach with three parts water. Pour the mixture into a hand sprayer, similar to that used for spraying starch onto clothing. Be aware that while this application process can be time-consuming, it is essential to ensure complete saturation. Allow the chlorine bleach solution to remain on the roof for between ten to fifteen minutes, and then rinse with warm water from a garden hose. Finally, examine the roof for remaining mold. If any mold still exists, repeat the process, being sure to rinse the roof after each application of chlorine bleach.

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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.


Can You Please Tell Me What This Might Be I Have This All Over In My Attic Some Spots Are Just Patches Here And There And Others Are Big Areas I Have Obvious Moisture Stains In The Attic And The Roof Is Sagging And Not Properly Installed Does This Look Like Mold

This looks like light attic mold growth. If the roof is sagging/failing, I recommend contacting a roofer. The sagging can occur from leaks or excessive condensation. Youll likely need additional roof ventilation, air sealing of the ceiling and improved ventilation inside the home. The latter is important because it lowers the amount of humidity that enters the attic space in the first place. This lessens the burden on the attic ventilation.

Read Also: Mold On Shower Grout

Apply A Moisture And/or Microbial Barrier

Roofing materials and technology has advanced greatly within the last few decades.

One of those advances is the ability to apply chemicals to your existing roof that repels water, or prevents algae and mold from developing. New roofs are often constructed of materials that have these properties impregnated into them.

Thankfully There Are Some Killer Alternatives To Bleach

How do I clean my roof shingles? Roof cleaning made easy

1) Sodium hydroxide products are NOT recommended!! A chemical alternative to bleach uses theantifungal agent sodium hydroxide… also known as lye. Lye-based products appeared on the market a few years ago, but turned out to be even more dangerous to use than bleach! Even at low concentrations, permanent damage could be done to the roofing, possibly even dissolving the roofing nails!

Fortunately, most lye-based products have been removed from the market.

2) Here are a few bleach-free chemical treatments that can help keepfungus under control:

Moss Out! from Lilly Miller Brands

Moss Out! comes in a number of formulations, one specifically for roofs and others designed to remove and/or inhibit moss and fungus growth on siding, masonry surfaces and even lawns. Their formulae use tried and true zinc compounds that linger on surfaces to provide continuing protection from fungus regrowth.

Read Also: Basement Mold Removal Diy

Vinegar Solutions Work Against Moss

A solution of equal parts apple cider vinegar and water has long been touted as an effective herbicide and pesticide. Using it does kill algae and moss, but not mold.

And caution must be taken to protect nearby bushes and plants because overspray will damage them. Vinegar quickly changes the pH of the soil making it inhospitable to most plants.

How To Get Mold Off Wood Floors And Other Surfaces

If you find traces of any type of fungi on your ceiling, floor, or another surface, follow these steps:

  • Wear Protective Clothing

Its a good idea to wear protective clothing when you spray against mold, as well as an N-95 respirator, gloves, and safety goggles.

  • Find the Source of the Mold

Because of the high percentage of humidity, its very probable that mold comes from the bathroom, particularly sinks and toilets. Also, its good to check if there are any broken pipes or some kind of water damage. Keep an eye out for any water leaks or cracks on the walls of your house.

  • Clear the Entire Room So You Can Clean It Off

To get the best results when setting out to clean the mold off wood, get as many furniture items out of the infested room as you can. Its important to have free space, so you can maneuver more effectively.

  • Make a Cleaning Product

You can use some of the recipes I provided in the article, Borax, strong alcohol like vodka, a powerful detergent solution, a vinegar mixture, or hydrogen peroxide.

  • Start Wiping the Room With Wet Cloth Material

After using any of the solutions, you should wash off the spot with a wet cloth, and later use a dry one to remove the water.

  • Alternatively, Use Some Other Product and Spray It on the Surface

If the infestation is particularly large, the best way to kill mold on wood would be to use the disinfectant Sporicidin or a chemical mold blocker like Mold Armor.

  • Sanding the Area

Also Check: What Causes Mold In Bathroom Ceiling

How Can Homeowners Discourage Algae And Moss From Growing On The Roof

Trees overhanging the roof can encourage algae and moss growth. So trim back any overhanging branches. Twigs, leaves, and sticks that accumulate on the roof should be promptly removed with a leaf blower. Always direct the airflow down the slope of the roof, so debris doesnt get stuck under the shingles.

Keep the gutters clean and clear. If a higher roof is draining onto a lower roof, thats a recipe for algae and moss growth. A simple fix is to direct the downspout of the upper roof into the lower roof gutter.

If youre due for a roof replacement, then installing algae-resistant shingles is an excellent way to prevent unsightly algae growth. Algae hate copper, and you can also put strips of copper under the shingles nearest the roof peak. This will prevent future algae cells from making your roof their home. You can also replace your old asphalt shingles with new ones in a darker color to hide streaks and stains.

I Just Had A Roof Replaced On My House New Osb Sheathing And Added On Deck Intake Vents For Ventilation Along With Ridge Cap Vents Has Not Been A Month And Went Into The Attic And Noticed Almost All New Osb Has White Fuzzy Mold Growth Roofing Company Is Supposed To Come Out Next Week To See Whats Going On

Removing Mold from Your Roof by a Roofing Contractor ...

The amount of regrowth is high for only a month. Is there any chance the OSB was saturated during the reroof? I.e. was it rained on prior to install? This certainly would explain the regrowth in an otherwise dry attic. Also, I see signs of past growth on the adjacent framing. This indicates a long term moisture issue in the past.

Here are a few items I recommend investigating:

  • Verify the qty of upper roof ventilation. RVOs should be installed every 4-6 just below the ridge line.
  • Verify the sheathing/OSB was cut correctly to match the new vents. Often the vent holes dont line up with the new vents, limiting the air flow.
  • Soffit vents should be present in every other framing bay . Check to ensure no insulation is blocking the soffit vents.
  • Ensure all bathroom/kitchen exhaust ducts are properly connected to dedicated roof vent caps. Often these are accidentally disconnected during the reroof process.
  • Read Also: How To Mold Leather Holster

    How To Get Rid Of Algae On The Roof

    You could replace all the roofing with new shingles dark enough to disguise the staining, or with shingles laced with copper granules, which are lethal to algae. But that would only make sense if the shingles were worn out.

    The less expensive solution is to spray wash the roof with a 50 percent mix of water and bleach to get rid of the algae. Just be sure to wet your foundation plantings first, and rinse everything in clean water when youre done. Plants dont like bleach, and wetting them with plain water first protects them.

    What If I Like The Moss

    Some homeowners find moss enchanting, like ivy growing up the side of their home. If youd like to grow moss or other plants on your roof, you could consider investing in a residential green roof. Thin, extensive green roofs are enough to grow succulents and mosses. If youre interested in taller plants, consider an intensive green roof.

    Read Also: Cleaning Mold On Bathroom Ceiling

    How To Get Rid Of Algae And Mold

    If your roof is super bad, make sure you consult someone professional before taking action. Why spend money cleaning a roof when it needs a repair. In that same vein, why repair a roof when it just needs a cleaning? But luckily most of the time to remove algae and mold your roof will just need a good, thorough cleaning.

    One way to clean the roof of algae and moss is with a brush and a little grunt work, scrubbing and separating the greens from the roof. Brushing should start at the top and work down, as going up could mess up your shingles. Bleach shouldnt be used either because it can damage your roof. You should use an environmentally friendly and safe roof cleaning solution.

    Should You Remove Moss

    how to clean mold off asphalt roof shingles with bleach

    When you get a roof replacement, you may want to have your roofers install the new roof over top of the old. In certain circumstances, this can help you save money. However, if your old roof has moss growth, can you still use this method?

    You may need to deal with the moss before the full roof replacement. Your roofers will need to remove all the shingles on your old roof, or they may need to remove the largest chunks of moss with a pressure washer and then apply the new roof. It is only advisable to use a pressure washer because you no longer need to worry about the condition of the old roof. The new one will offer the protection your home needs.

    Recommended Reading: Skin Rashes From Mold

    The Benefits Of Removing Moss

    While you may not necessarily have to remove the moss-covered shingles before a new roof installation, you should consider it. There are many benefits of removing the moss-covered shingles, including:

    • Reduce long-term costs: By removing the old roof, you keep the opportunity to double-up roof layers during your next roof replacement. The maximum layers of shingles allowed to be on the roof, according to most building codes, are two. So, once you use this strategy, you must tear off both roof surfaces during your next roof replacement.
    • Maintain home value: Are you planning on selling your home soon? A properly replaced roof is more likely to appeal to potential buyers, while a poorly replaced roof may negatively affect your home value.
    • Avoid the risk of damage: You can avoid all of the risks listed earlier in this article by simply removing all of the moss-covered shingles.

    What Causes Roof Mold

    Roof mold is caused by moisture, so the best way to prevent it from growing is by controlling your humidity levels!

    Mold colonies or black stains on roofs are a possible sign of humidity in the structure. The mold may rise from soaked areas such as leaky pipes, overflowing drains, clogged gutters, and downspouts also from condensation on walls and ceilings.

    During certain seasons, it is typical to notice an increase in mold on roofs. Roof design, exposure to sunlight, and the amount of rainfall are all elements that affect mold growth.

    Roof Design The design of the roof is important to determine how likely it is for molds and mosses to grow on roofs.

    Steep slopes will probably not allow mold colonies as they would dry quite quickly, whereas flat roofs with a longer time spent in the shade are more prone to issues.

    Proper Drainage A roof needs efficient drainage so that rainwater does not remain anywhere. If the drainage is working properly, rainwater will run off immediately and will reach gutters quickly.

    This way it can be directed to downspouts leaving no opportunity for mold growths on roofs.

    Sun Exposure Roofs that are mostly in direct sunlight do not allow molds to grow as they dry fairly quickly.

    On the other hand, roofs that are mostly covered by trees or buildings can stay very humid and promote mold growth if proper sunlight exposure is not provided.

    Mold growths are thus more common in regions where rain is abundant throughout the year.

    Recommended Reading: How To Remove Mildew From Ceilings In Bathrooms

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