Do you ever notice black spots on your roof? It’s probably algae or moss, not mold or mildew like most people think. Algae and moss feed off moisture and materials in asphalt shingles.
If you’ve neglected to regularly clean your roof, algae and moss buildup can be tough to get rid of.
When was the last time your asphalt roof was cleaned? Properly maintaining your asphalt roof is key to improving its lifespan. That’s why our roofing experts are here to teach you all about how to clean roof shingles.
How to Clean Your Shingle Roof
Moss and algae spores are carried by the wind (or animals), eventually landing on your roof. Odds are, if your neighbor’s roofs are plagued with dark spots, yours probably will be, too — unless you clean it off before it gets worse!
Don’t wait until your roof is covered with black moss or green algae. Here’s how to keep your asphalt shingle roof clean.
Wash Your Roof With a Cleaning Solution
Killing algae and moss at its source requires the right cleaning chemicals. However, don’t just opt for a super strong cleaning solution. Use a cleaner designed to remove algae and moss.
Typically, a roof cleaning solution is a mixture of:
- Water
- Chemical cleaner for moss and algae
- Bleach
Add your cleaning solution to a spray bottle and wet your entire roof. You’ll usually let it sit for 15-20 minutes before washing it off with a hose or soft washing machine.
If you use a bleach solution, ensure your surrounding landscaping is safe. Either avoid spraying it or cover it with plastic to keep it safe.

Scrub Shingles With a Soft-Bristled Brush
A cleaning solution alone isn’t enough to remove stains on your roof. You’ll need to scrub the shingles with a soft-bristled brush or broom to get the tough stains out.
It’s best to scrub with a cleaning solution that helps remove dirt and algae and periodically rinse the roof while scrubbing so the cleaning solution doesn’t dry up.
Clear Debris
Use a leaf blower to eliminate any debris on your roof as part of ongoing maintenance. You don’t have to wash the roof whenever you want to clear debris off, simply blowing away excess leaves and dirt is enough.
Keeping your gutters clean is crucial for proper water drainage. If your gutters are clogged, water will pool on your roof, causing moisture damage.

Why Do I Need to Clean My Shingle Roof?
Yes, it’s important to clean your asphalt shingle roof regularly. You need to get ahead of any moss, dirt, and algae buildup before it sets in.
When it isn’t cleaned off properly, moss can shorten the lifespan of your roof by weakening each shingle. An asphalt shingle roof should last around 12-30 years, but that’s only with the proper maintenance.
Here’s why it’s important to keep your shingle roof clean.
Improve Curb Appeal
Algae mostly just affects the aesthetics of your roof — large black spots and steaks don’t do much for your home’s curb appeal.
Prevent Damage from Moss Buildup
Moss poses the biggest threat to your roof besides the weather, as it can severely damage asphalt shingles.
As moss grows, it can get underneath your shingles, causing the edges to curl up. This makes them more susceptible to blowing off during bad weather and increases the risk of water damage to your roof.

Can I Clean My Roof Myself?
Yes, you can clean your roof yourself. However, we don’t recommend this as cleaning your own roof can be dangerous.
Even if it’s a flat roof that’s easy to walk around on, it’s still easy to slip and fall once you spray the cleaning product on your roof.
Plus, if you DIY your roof cleaning, you might not mix the chemicals correctly and could end up damaging your roof. Not to mention, surrounding landscaping can easily be damaged by the products used to clean your roof.
How Do Professionals Clean Roofs?
Professionals are highly trained and experienced when it comes to cleaning roofs.
In general, here’s how a professional will clean your roof:
- Use a chemical mixture that kills algae and moss yet isn’t damaging to surrounding landscaping
- They use soft washing, not pressure washing, to clean your roof without damaging it
- Professionals will scrub your shingles with a soft bristle brush to get rid of tough stains
- Carefully scrape the moss off
- Utilize proper safety harnesses and equipment as necessary
- Apply a long-lasting algae and moss killer to prolong the health of your roof

Tips for Keeping Your Shingle Roof Clean
- Clean debris off the top of the roof and out of the gutters
- Cut back trees that shade your roof. The more sunlight hitting your roof ,the more difficult it is for moss and algae to grow
- Clean your roof on a cloudy day. The sunnier it is, the quicker your cleaning solution will evaporate on the shingles. Cleaning your roof on a cloudy day allows the chemicals to sink in.
- Don’t wait until your roof is stained with moss and algae to clean it. You should clean your roof regularly to prevent stains from happening in the first place
Looking for Roofing Experts in Indiana?
While we don’t offer roof cleaning services, we provide premium asphalt roof installation throughout Northeast Indiana, Northwest Ohio, and Southern Michigan.
Contact us today for a FREE roofing estimate!
Written by Shield Exteriors: Our team of experienced roofers has been in the business for decades. We want to help educate homeowners on everything they need to know about residential roofing, from how long certain types of roofs last to picking the roofing material best for your needs and budget. Learn more about us or contact us today if you’re looking for a roof estimate!