If you reside in regions like the South like Greenville SC, which experience warm and humid summers, you may have noticed stains and streaks on your asphalt shingles. While these blemishes resemble mold, a significant portion of what appears to be mold is actually blue-green algae known as Gloeocapsa Magma. Additionally, in some cases, the growth may be classified as moss rather than mold.
Differentiating between these substances is important, as mold can pose health risks to your family and can be more challenging to eliminate.
Guide for algae and moss removal from your roof
Identifying Roof Algae: Dark Spots Guide
Dark streaks across your roof are commonly attributed to algae growth. Algae spreads through wind, birds, and other animals, affecting homes across various parts of the United States.
This type of algae begins its life cycle as airborne spores that settle on roofs, particularly those with asphalt shingles. The northern-facing side of roofs is more susceptible to algae survival and growth, as it receives less UV exposure and retains moisture from morning dew and rain for longer periods.
As the algae proliferates, it forms large black streaks on your shingles. Identifying and removing it can be a challenging task, which is why this roof algae guide is crucial for addressing potential algae growth on your roof.
Preventing Algae from Returning
After successfully removing algae from your roof and taking measures to minimize contributing factors like tree overhang and standing water, you undoubtedly want to prevent algae from reoccurring. As part of this roof algae guide, you can use certain metals to hinder algae growth.
Zinc or copper flashing is an effective method to deter algae growth, and it can be installed around chimneys and vents. However, the most efficient way to prevent algae on your entire roof surface is to install a few inches wide strip of zinc or copper just below the row of shingles near the roof peak.
When it rains, the molecules shed from these metals wash down the shingles, effectively killing algae. Although copper and zinc may be costlier than stainless steel or aluminum, the investment will pay off by extending the lifespan of your shingles.
Moss: A Less Common Occurrence
If you notice green fuzzy growth on your roof, it is most likely moss. Moss thrives in cool and damp environments. It tends to appear on the north slopes of roofs and areas shaded by overhanging trees or roof sections, where moisture lingers, promoting moss growth.
Similar to algae, moss spores can be carried by wind, birds, squirrels, and other small animals, finding their way onto roofs.
Once moss spores settle on a roof, they accumulate in the groves between shingles and eventually develop into dense and spongy moss patches.
Differentiating Moss and Algae
Although moss and algae often share the same location on your roof, they are distinct entities.
Moss typically appears greener and has a fluffier texture compared to algae, although it may appear browner during dry seasons. Moss grows upwards from the roof surface, while algae remains flat and flush with the shingles and fixtures. Algae can display various colors such as gray, blue, green, or brown.
While a small amount of moss is harmless, allowing it to grow unchecked can damage your shingles if they are asphalt. Moss should be removed as soon as possible. On the other hand, algae fosters the growth of mold, which can lead to severe issues. It is crucial to remove algae quickly and efficiently.
Guide for Removing Moss on Roof
Tackling Moss, Algae, & Mold
We recommend seeking professional assistance for roof algae and moss removal. However, if you are a capable DIY enthusiast who can safely climb a ladder and are not afraid of heights, you may attempt the removal yourself.
The safest method for your roof and the environment involves using products such as Spray and Forget. These can be purchased at most local hardware stores, applied with a hose-end sprayer, and in some cases, sprayed from the ground, a ladder, or the edge of the gutter. These methods may take 3-6 months to yield results but are the safest option. It is important to research these products before use.
For quicker results, a more aggressive method involves using a water and bleach solution. Here are the general steps for this method:
- Mix 1 part bleach cleaner with 1 part water. (For a stronger cleaning solution, add ½ cup of trisodium phosphate per gallon of mixture.)
- Pour the solution onto the affected area of the roof and let it soak for 30 minutes. For larger sections with algae or moss, you can use a spray pump to apply the solution.
- Allow the mixture to sit for approximately 30 minutes. During this time, the chemicals will kill the algae and moss, loosening their grip on your roof.
- Take precautions to cover any plants you wish to protect, as the solution may harm them. Rinse or wet everything the solution may come in contact with.
- After 30 minutes, rinse off the mixture using a low-pressure setting on your hose. The moss will not immediately detach from your roof, but within a few days, it will dry up and be blown away by the wind. If your roof is heavily covered in moss, you may need to use a leaf blower to remove any remaining residue.
Please note that working on your roof can be risky and may lead to additional issues. While moss and algae removal can be attempted on your own, we highly recommend hiring a roof professional with the expertise to safely and effectively remove these unwanted organisms or plants.
Tips for Preventing Roof Moss
Moisture and bacterial growth are the primary causes of roof algae and moss. By preventing their growth, you can ensure a longer lifespan for your roof. Here are a few tips to prevent future growth after removing moss and algae:
- Trim trees near your home: Overgrown trees can transfer bacteria to your roof and contribute to algae growth. Plant trees at a sufficient distance from your house and regularly trim them to prevent branches from hanging over the roof.
- Address standing water: Standing water promotes mold and algae growth. Minimize standing water on your roof by repairing damaged shingles, performing necessary roof repairs and cleaning gutters.
Prolonging Your Roof’s Lifespan
Unchecked moss and algae growth can significantly reduce the lifespan of your roof. However, there are several steps you can take to extend its longevity. These measures involve keeping your roof clean and free from debris and growth. Consider the following tips:
These suggestions all revolve around the idea that maintaining a clean and organized roof will ultimately increase its lifespan. Additionally, removing moss and algae from your roof will contribute to its proper functioning over an extended period. Refer to these tips to help prevent growth and maintain your roof’s condition.
For a reliable roof inspection and an effective way to extend your roof’s lifespan, reach out to KM Roof and Home Repair. We offer sustainable and affordable treatments that can add up to 15 years to the life of your roof. Some of our dealers may also provide roof.
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