Is Your Roof Growing Algae? Here’s How to Safely Clean It
If you’ve noticed dark streaks on your roof that weren’t there a few years ago, chances are you're dealing with algae. It's more common than you think—especially in humid areas like Massillon. Many homeowners search for “power washing services near me” to solve the problem, but before you grab a ladder or call a contractor, here’s what you need to know.
This article walks you through what causes roof algae, why it's more than just a cosmetic issue, and how to safely clean it without damaging your home.
What Is That Green (or Black) Stuff on My Roof?
Algae—specifically Gloeocapsa magma—is a type of bacteria that feeds on the limestone filler in asphalt shingles. It thrives in warm, damp environments, and can spread quickly, especially in shaded areas that don’t dry out after rain.
Algae can appear as:
Black streaks running down your roof
Greenish patches near gutters or chimneys
A general darkening or mottled look on the shingles
While algae won’t destroy your roof overnight, it can shorten its lifespan by trapping moisture and increasing wear and tear.
Why You Shouldn’t Ignore Algae Growth
A stained roof might seem like just a cosmetic problem, but algae can have real consequences for your home:
Decreased curb appeal: Algae streaks make your home look older and less well-maintained.
Reduced efficiency: Algae-covered shingles absorb more heat, making your home warmer and your energy bills higher.
Premature wear: Trapped moisture can lead to rotting underlayment or mold inside your attic.
Bottom line? The longer you wait, the more damage (and cost) you could be facing.
How to Clean Roof Algae the Right Way
There’s a right way and a very wrong way to clean algae off your roof. The key is to use gentle methods that preserve the integrity of your shingles. Here’s a safe, step-by-step approach:
1. Choose the Right Cleaner
Use a solution of water and oxygen bleach, or a commercial cleaner specifically labeled as safe for asphalt roofs. Avoid straight bleach—it can damage shingles and kill landscaping.
2. Apply from the Ground If Possible
If you can, apply the cleaner using a pump sprayer from the ground or a sturdy ladder. Never walk on a wet roof—it's slippery and dangerous.
3. Let It Soak
Allow the solution to sit for 15-20 minutes. This gives it time to break down the algae without harsh scrubbing.
4. Rinse Gently
Use a garden hose with a nozzle to rinse the cleaner off. Don’t use a high-pressure washer on the roof—shingles aren’t built for that kind of force.
When to Call in the Pros
If your roof is steep, high, or heavily affected by algae, it’s best to leave the job to professionals. Companies like Wilhelm Painting & Power Washing offer expert-level roof cleaning as part of their exterior cleaning services in Massillon. They know how to treat algae without damaging your shingles or voiding your roof warranty.
Plus, pros can inspect your roof during the cleaning process and catch any small issues—like loose shingles or clogged gutters—before they turn into big problems.
Case Study: A Cleaner Roof, A Happier Home
Massillon homeowner Lisa noticed dark streaks spreading across her roof in early spring. After a quick search and seeing great reviews, she contacted Wilhelm Painting & Power Washing. Within one afternoon, their team cleaned her entire roof using a safe, eco-friendly method. Not only did her home look brand new, but she also learned that algae had started to creep into her gutters—a problem she was able to fix early, thanks to their thorough inspection.
Take Action Before It Spreads
If you’ve spotted signs of algae on your roof, don’t wait until the problem gets worse. Whether you try a gentle DIY method or hire the pros, keeping your roof clean protects your home’s value and longevity.
Ready to tackle roof algae the safe way? Reach out to a trusted local expert like Wilhelm Painting & Power Washing and ask about their professional roof cleaning services.
