The Dangers of Roof Algae and How to Prevent It

Roof algae is probably not one of those things that keeps you lying awake at night. However, Forbes estimates that the average household spends $1,169 on roof maintenance each year, so maybe roof algae and the significant damage it can cause deserve more attention. 

Roof algae does more than just damage the aesthetic appeal of your roof. If left untreated, it can cause serious problems that could require costly repairs. In this post, we will take an in-depth look at what roof algae is, the damage it can cause, and the preventative measures you can take.

Roof Algae 101: Know Your Enemy

As you drive around your neighborhood, you will probably notice that some homes have black streaks on their roofs. This isn’t dirt or grime; it is Gloeocapsa magma—the scientific name for a type of bacteria that loves roofs and what we commonly call roof algae (it is not actually a type of algae, but that is a topic for another day).

This bacteria forms a growth on your roof by feeding on two things: limestone filler in your shingles and moisture in the air. In humid climates like Atlanta, where the summer is considered oppressively humid more than 21 percent of the time, roof algae can thrive. Algae also love sunlight, which Georgia provides in abundance. 

If left unchecked, roof algae growth can affect your home’s curb appeal and cause significant damage to roofing materials.

Dangers to your roofing system

Roof algae is particularly harmful to asphalt shingles and the structure of your roof. Some key concerns include:

• Damage to roofing shingles: If left untreated, roof algae will eat away at the limestone in asphalt shingles. This is particularly common in older homes that do not have algae-resistant shingles. Weakened shingles can break down and cause other problems for your roofing system.
• Moisture retention: Shingles that have been damaged by roof algae develop cracks that can hold moisture on the roof surface rather than encourage it to flow into the guttering system. Thus, roof algae indirectly contributes to the deterioration of your roof.
• Structural damage: Weakened shingles no longer protect the fabric of your roof. If left untreated, moisture can penetrate your roof, which promotes the growth of fungi that can eat away at roofing materials. 

Consequences of untreated algae growth

Algae growth does more than just damage your roof shingles and structure. It can also cost you money and affect your health every day.

Significant growths of roof algae are darker than the original shingles. Your roof may no longer reflect UV rays as effectively, meaning it absorbs more heat. That is bad news for your air conditioner, which has to work harder and use more electricity to keep your home cool.

While roof algae is not directly detrimental to human health, it can cause dangerous conditions. Damp conditions can promote mold growth in your attic or roof space. According to WebMD, mold can cause health concerns, including allergies and respiratory issues. 

Preventing Roof Algae Growth

Roof algae spores travel through the air, looking for a suitable roof to call home. Algae particularly like roofs with the following conditions:

• Overhanging branches
• Organic debris, such as leaves from nearby trees
• Clogged gutters, with standing water leading to secondary moisture retention issues

It may be tempting to try a DIY approach to algae cleaning—but be warned. All roof work is inherently dangerous and requires the right safety equipment. It pays to work with a professional roofing contractor who can safely carry out the following tasks to remove algae and prevent algae growth in the future.

Trim your trees

Trimming overhanging branches can help prevent algae growth and minimize other risks to your roof. It also reduces the amount of leaves and twigs that fall on the roof and cause clogged gutters. 

However, trimming overhanging trees is definitely not a DIY project. Talk to roofing professionals for a quote to tackle this problem while they address other issues.

Unclog your gutters

Clogged gutters cause standing water, leading to moisture retention in shingles and other roofing materials. This can lead to mold and roof algae developing and can weaken the wooden structure of your roof. Schedule gutter cleanings at least twice a year, in spring and fall, to keep moisture flowing away from your roof and prevent roof algae growth.

Invest in algae-resistant shingles

If the time has come for a roof replacement, your choice of roofing shingles could help prevent algae growth from becoming an issue in the future. Algae-resistant shingles have copper or zinc granules embedded in them. Over time, these metals release ions that inhibit the growth of roof algae.

Install zinc or copper strips

Metal strips not only add to the aesthetic appeal of your roof but also do a great job of preventing roof algae. Every time it rains, zinc or copper strips release tiny amounts of metal ions that wash down the surface of your roof. These trace amounts of metal not only prevent algae growth but can also inhibit mold and moss development.

Schedule regular roof cleaning

You can prevent algae growth and extend your roof’s lifespan with regular cleanings. This is not the time to get out the power washer, as the force of the water can damage your roof shingles. Also, do not be tempted to wash your roof with chlorine bleach. It may remove the surface algae, but it does not treat the underlying problem and can lead to rapid—and worse—algae regrowth.

Instead, your roof needs a thorough cleaning with a soft-bristle brush and specialist roof cleaning chemicals. Again, this is a job best left to roofing professionals, who can carry it out quickly and safely.

Why It Pays to Hire Roofing Experts

Roof cleaning and maintenance may sound like a Saturday morning DIY job. In reality, that is unlikely to be the best way to tackle roof algae and prevent it from coming back.

Investing in professional cleaning and regular roof inspections can bring the following benefits:

• Catching algae early before it wreaks havoc on roofing materials
• Carrying out roof cleaning safely and quickly, using industry-approved methods and appropriate chemicals that will not damage your roof or nearby plants
• Getting advice on long-term solutions like copper strips, algae-resistant shingles, and roof ventilation
• Discussing roof replacement options if there is extensive damage to the roof shingles or structure

If you do decide to hire a professional roofing contractor, make sure you choose a name you can trust that truly understands the local climate and the roofing systems that work best.

Choose Findlay Roofing—Georgia’s Go-To Roofer

Keeping your roof free of algae and in good repair is about much more than maintaining its curb appeal. You can extend your roof’s lifespan, avoid costly repairs, and reduce your exposure to health risks. If you have decided it is time to call in the roofing professionals, turn to Georgia’s most trusted and recommended roofer—Findlay Roofing.

For over 30 years, we have been repairing and replacing roofs in the Atlanta metro area and leaving satisfied customers in our wake. As Georgia’s largest full-service roofing contractor, we bring our unparalleled experience and Georgia-specific knowledge to every roofing job. 

Our work is fully insured, giving you confidence that your roof is in safe hands, whether your job is big or small. To learn more about our lifetime, Leak Free Warranty and schedule a service, call (470) 570-6497 or complete our online contact form, and we will get back to you very soon.