Have you noticed unattractive black streaks running down your roof and wondered what causes them? Most homeowners assume that these streaks are caused by any number of things ranging from mold and mildew to soot. The real cause of these unsightly marks on your roof is algae.
The reason most people don’t consider algae is because we think of algae as being green. This variety, however, forms a dark pigmentation that coats its exterior and protects it from the harmful UV rays of the sun.
These algae growths are most common on asphalt shingles, although they can be found on any type of roofing. They begin as small spots that homeowners typically overlook. Then, after several months, they become the black streaks we see.
What causes algae growth on my roof?
Spores propagate the algae that grow on your roof. These spores can be spread very quickly, as they are airborne. Birds, animals, and wind carry the spores and disperse them throughout neighborhoods.
Moisture is a contributing factor to algae growth, as well as the effects of sunlight. Since coastal climates tend to be warmer and more humid, they are particularly conducive to algae growth, but it has become a problem across the country, even in colder regions. Sunlight is a factor that you will understand if you mainly see algae on the north side of your home. Since the north side of the roof tends to get the most shade as the sun moves through the sky, moisture accumulates more there, which creates an environment that is just right for algae to thrive.
What do these streaks mean for the viability of my roof?
Other than making your roof look unattractive and damaged, the most significant effect that algae will have on the shingles involves their longevity. The algae that form on your roof are not dangerous or harmful to you or your family, but it causes the granules on the shingles to fall off. Since these granules are there to protect the roof from the sun’s UV rays, they begin to dry out as the granules wash away.
Another damaging element that algae growth creates is an environment that encourages the growth of fungus. Fungus is also spread through the air, and when it lands on your roof, it can combine with the algae to form lichen. Lichen feeds off the shingle filler, which acts to erode the roofing material further. It also creates roots, which makes it difficult to remove. For this reason, it is vital to move quickly to remove algae from your roof.
How do I get rid of algae on my roof?
There are several options when it comes to cleaning the algae from your rooftop. Many homeowners attempt to clean the roof themselves, while others choose to hire a professional cleaning service. Hiring a professional to do the job is always the best course of action when it comes to an investment as large as your roof, but DIYers can accomplish the task with a little research and preparation. Regardless of which option you choose, consider the type of cleaning solution that is used and how it affects your landscaping, pets, and wildlife.
Most roof cleaning solutions contain trisodium phosphate, chlorine bleach, oxygen bleach, or lye. Lye is a very effective choice, but it is also a corrosive substance that can be dangerous to use. Anyone applying this type of solution should be wearing full protective gear. Chlorine bleach is often a practical choice for homeowners. If you are looking for the most environmentally friendly option, you will want to go with oxygen bleach.
How do I clean my roof myself?
If you choose to clean the algae from the roof yourself, keep in mind that this may void your roof warranty, so you may want to check your warranty specifics first. Also, it is crucial that you never use a power washer on your roof. Power washing equipment, even on a low setting, will damage your shingles, and will most certainly void your warranty.
You should clean your roof on a cool, overcast day with little wind, because it ensures the best conditions for effective cleaning, and prevents your cleaning solution from traveling on the wind. You will need protective clothing, slip-resistant shoes, protective eyewear, rubber gloves, and a pump garden sprayer.
Fill your sprayer with the cleaning solution and apply it to the roof in long, even strokes. Start at the top and work your way down in 4-foot wide sections. After 15-20 minutes, wash the area down with a garden hose. Be sure to avoid standing in wet areas throughout the entire process, as they will be very slippery.
Consider hiring a professional
Although it is possible to clean the algae from your roof yourself, it is always best to hire a professional roof cleaning service to do the job most effectively. A professional service will ensure that you do not void your warranty, and they will have the experience to avoid any danger of slipping and being injured.
Another benefit is that they have knowledge of the best products to use, and which will be safest for your landscaping, family, and pets. Regular roof maintenance by a trusted professional is the best way to avoid costly problems in the future and prevent algae from returning to your roof.
If your roof is showing signs of algae growth, call in a professional to assess the situation and protect your shingles from damage. Call the experts at Able Roof today at (614) 444-2253 to schedule an appointment and guarantee a longer lifespan for your roof.