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How to Get Algae off Roofs


North Carolina summers are hot and humid, and with that humidity comes roof algae. That ugly blue-green bacteria is more than just an eyesore, it’s damaging your roof, but the good news is that it can be removed and avoided. 

If you are researching “How to get algae off my roof?” you’ll be interested to learn more about what it is and how to get rid of it. 

How to Get Algae Off My Roof

The blue-green growth you see on your roof is described by many as black algae or mold when in reality, it’s a bacteria called Gloeocapsa Magma. It’s a plant without leaves or roots, and it does not flower. It grows in environments with high levels of heat and moisture — like the humid climate in Greensboro, NC. 

The algae can look like dirt or mold from below, and this fungus starts with one spore that finds its way to your roof. 

Algae needs nutrients to grow on your roof, and the limestone filler used in many roofing shingles provides those nutrients. 

It thrives in the damp and shady area of your roof, especially under large overhanging branches that provide shade or where there are clogged gutters. The algae will spread and become darker as it nourishes itself on your shingles.

The algae growth starts with one spore, which can blow onto your roof or be carried by a bird, but it can only survive and thrive if the conditions are right. It loves the rain, standing water, inadequate roofing ventilation, and porous roofing material. 

If neighboring houses have the algae on their roofs, chances are it will blow onto yours at some point. The key is to ensure that you create an environment that will deter it from settling in and growing.

Algae Roof Damage

Because algae growth damages your roof, it’s appropriate to spend time researching “How to get algae off my roof.” As algae need moisture to thrive, it retains the moisture, damaging shingles and eventually rotting them completely. 

The algae spores grow on asphalt shingles that do not get a lot of sun exposure, as well as wood shingles or shakes. Algae also thrive in gutters and downspouts.

Algae feed off the limestone filler in your shingles, which weakens the roof’s structural integrity. Shingles can detach and expose your property to leaks and water damage, and the algae damage reduces the roof’s ability to reflect sunlight. 

When your roof cannot adequately reflect sunlight, the house will heat up more and require extra work to cool and regulate the indoor temperature.

The Effects of Roof Algae

Not only will unremoved algae eat away at the limestone filler of your shingles, but it has the following negative effects:

  • Decreases curb appeal, as it looks dirty
  • Deceases your home’s resale value
  • Can cause permanent roof stains
  • Causes wood rot
  • Shortens the lifespan of your roof

The sooner the algae are removed from your roof, the less damage it will incur. 

Different Types of Roof Bacteria

Blue-green algae are a problem for your roof, but other types of growths also thrive on your roof and can cause damage.

  1. Mold 

Mold is the result of algae on the roof which has not been removed. Algae retain moisture and remain damp, which causes roofing materials to rot slowly. Once the rot sets in, the mold will grow and flourish. 

Mold spreads rapidly and is dangerous to the structure of your property and your health. Roof mold and algae look very similar, but a roofing company will be able to identify them.

  1. Lichen

Lichen is a combination of fungi and algae that live together. It’s not as thick as moss, and it looks like a thin greenish crust on the roof. It grows in patches that sit close to the surface of the roof.

  1. Moss

Moss is a lot easier to identify because of its thick, green, grass-like appearance. It collects dirt from the air, which helps it grow, as it doesn’t have a root system. It can be a small patch or a large one if left to grow. In damp and humid conditions, moss can grow underneath the shingles and displace them, causing leaks. 

Any type of growth on your roof requires identification and removal by an experienced roofing company. Unfortunately, sun exposure isn’t enough to treat the growth once it starts, and the longer it’s left untreated, the greater the damage will become.

DIY Algae Removal? Not a Good Idea!

It can be very tempting to try to remove the algae yourself, but there are several good reasons why this is a bad idea. 

  1. Roof Damage

Algae growth that has gone undetected or untreated for a while can cause damage to your roof. Your roof needs to be inspected for damage and to ascertain the extent of the growth before it is treated. Your local roofer knows what to look for and the best way to remove the algae.

  1. Chemical Hazards

DIY treatments to remove roof algae can harm plants, the environment, and your own health. Once algae have been removed, it needs to be kept from reappearing.

  1. Accident Risk

Your local roofers are experienced in climbing roofs, removing algae, and performing repairs. They have the safety equipment and follow strict procedures to keep them and your property safe.

  1. Roof Repairs

People are tempted to treat algae growth on their roofs to save some money. However, without the experience necessary to remove the algae, you could inadvertently damage your roof and cause costly repairs. 

Applying solutions such as bleach and water could also compound the problem if this mixture becomes trapped under the shingles and further damages them. Your experienced roofing company will remove the algae quickly and safely.

There’s really no way around it. Once you have blue-green algae on your roof, it needs to be removed, and that’s where you need the services of a reputable roofing company. Your local roofers have the experience and training needed to remove the algae safely and can advise you on how to keep the algae from reappearing.

Keep Algae Off Your Roof

Once the algae have been removed from your roof, the trick is to keep it off. There are measures you can take to deter the return:

  • Trim back overhanging branches
  • Promote direct sun exposure
  • Repair all leaks and pooling quickly
  • Schedule annual roof maintenance
  • Keep your gutters cleared
  • Install an algae protection roofing system

Prevention is always the best method. A GAF roofing system with StainGuard plus Algae Protection is your home’s best defense. Your local roofing company in Greensboro, NC, can provide you with a roofing system designed to combat algae.

Roofing Maintenance

Regular roof maintenance is necessary to keep your roof in pristine condition. Your local roofers will ensure that any growths on your roof are detected and treated early, and any leaks or damage are identified and repaired. Roof maintenance is a preventative measure to extend the life and quality of your roof.

Reliable Roofing Company in Greensboro, NC

Algae and other fungal growths are unsightly and can cause extensive damage to your roofing system if left untreated. They expose your home to mold hazards and structural damage. 

Carolina Home Specialists will remove algae growth from your roof and conduct a full inspection and roof repairs. We can provide you with a GAF roofing system plus Algae Protection to protect your roof from the humidity in Greensboro. NC. Call your expert local roofers at Carolina Home Specialists today for algae removal and treatment. 

Reliable Home Improvement Services

How to Get Algae off Roofs

Carolina Home Specialists is a premier exterior home improvement service company serving the Durham, Greensboro, Winston-Salem, and Chapel Hill communities in North Carolina. We also serve many surrounding communities.

If you’re in the Triad area and need a design consultant, please consider reaching out to our local roofing, windows, siding, gutters, decking, and fencing installation specialists. We’d love to help!

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