What's the best way to remove black streaks on roof? Find out!

Seeing Black Streaks On Roof? Don’t Power Wash Shingles!

As spring arrives in Oklahoma City, so does the challenge of maintaining the appearance and integrity of your roof. One common issue homeowners face is the growth of black streaks on roof caused by algae. While these streaks may seem harmless at first, they can significantly detract from your home’s curb appeal.

Many homeowners reach for their power washer as a quick fix. After all, that’s what’s used to clean black streaks out of the driveway, along the home’s exterior and even gutter system! But when it comes to cleaning black streaks off a roof, you should NEVER power wash your shingles!

Using a pressure wash or power washer can cause significant (and unrepairable) damage. High pressure water will lift and break the adhesive between shingles, and the underlayment below shingles. This can pave the way for leaks, water damage, and other problems. Not to mention, it knocks off the protective layer of granules on the single surface. 

So how can you clean your roof and avoid costly damage in the process?  In this blog post, we’ll delve into what causes black streaks on roofs and provide safer alternatives to effectively clean them without the use of a power washer!

What Causes Black Streaks On Roof?

Black streaks on roofs are typically caused by a type of bacteria, specifically Gloeocapsa magma. This organism thrives in warm, humid climates, making Oklahoma City a prime environment for its development.

Gloeocapsa magma under microscope showing individual bacteria cells that cause black streaks on roof
Gloeocapsa magma under microscope showing individual bacteria cells that cause black streaks on roof

Interestingly enough, the bacteria are often mistaken for algae because they are green and form colonies in small clumps. However, as the colonies grow, they develop a dark and hard UV-protective outer coating which leads to the appearance of dark streaks on the surface of the roof. 

Why Are Black Streaks So Common On Asphalt Roofs?

Unfortunately for homeowners, Gloeocapsa magma LOVE asphalt roofs due to the high amount of calcium carbonate and limestone in the filler layers of the shingles. Both act as a food source and help retain moisture longer. It also doesn’t help that this type of bacteria is airborne and can easily be spread from home to home. In areas with high humidity, it’s often not a question of if your roof will get black streaks, but when. 

Seeing Black Streaks? Don’t Power Wash Shingles!

While pressure washing may seem like a convenient solution for removing black streaks, it can actually do more harm than good. The high-pressure water can strip away the granules on asphalt shingles, leading to premature wear and tear. Additionally, pressure washing may force water underneath the shingles, increasing the risk of leaks and water damage.

To make matters worse, homeowners who choose to power wash shingles can’t file an insurance claim for any damage. That’s because these policies only cover unexpected damage or manufacturing defects. 

So how can you remove black streaks on your roof without damaging your shingles? Choose a safe cleaning alternative! 

Safe Roof Cleaning Alternatives To Power Washing 

Soft Washing: Soft washing is a gentler alternative to pressure washing that involves using a regular water hose and eco-friendly cleaning solutions. This will remove algae, bacteria, and other debris from the roof’s surface without causing damage.

soapy water being thrown onto roof shingles is best way to clean black streaks off of roof
soapy water being thrown onto roof shingles is best way to clean black streaks off of roof

Biodegradable Cleaners: There are several biodegradable cleaners available on the market specifically designed to remove algae, mold, and mildew from roofs. These cleaners can be applied with a pump sprayer or garden hose and left to sit for a specified period before rinsing with water. Be sure to follow the manufacturer’s instructions for best results.

side by side comparison of residential roof shingles before and after black streaks were cleaned off
side by side comparison of residential roof shingles before and after black streaks were cleaned off

Preventative Measures: To prevent black streaks from returning, consider installing zinc or copper strips along the ridge of your roof. These metals naturally inhibit the growth of algae and can help maintain a clean roof over time.

Key Takeaways On Removing Black Streaks On Roof 

Maintaining a clean and algae-free roof is essential for preserving the appearance and longevity of your home. While pressure washing may seem like a quick fix for removing black streaks, it can actually cause more harm than good. Instead, opt for safer alternatives such as soft washing and biodegradable cleaners to effectively clean your roof without risking damage to the shingles. By taking proactive measures and implementing proper cleaning techniques, you can keep your roof looking its best for years to come.

At Triple Diamond Construction, we understand the importance of proper roof maintenance, and we’re here to help. Contact us today for expert roofing services tailored to your needs.

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