Asphalt Roof Cleaning Tips for a Cleaner, Longer-Lasting Roof

By Top Dawg Pressure Wash Blog 0 Comments

Your roof does way more than just sit on top of your house—it’s your first line of defense against the elements. But over time, it can start looking a little worse for wear, thanks to moss, algae, lichen, and dirt. These unwelcome guests don’t just make your roof look dingy—they can actually shorten its lifespan. So if you’ve noticed black streaks, green patches, or a general “blah” vibe to your asphalt shingles, it’s time for a roof cleaning intervention.

But let’s pump the brakes—cleaning an asphalt roof isn’t something you want to tackle recklessly. The key is finding that sweet spot between doing the job thoroughly and avoiding damage. And luckily, this guide has everything you need to know! From pro tips to rookie mistakes to avoid, you’ll have all the info to clean your roof safely and effectively, whether you go the DIY route or call in the pros.

Why Cleaning Your Asphalt Roof Is So Important

If you have an asphalt shingle roof, you’re in good company—it’s one of the most popular roofing materials out there, thanks to its durability, affordability, and classic look. But let’s be real: even the sturdiest roofs need a little TLC. Algae, moss, and debris can wreak havoc on your roof over time, and the longer you leave it, the bigger the problems get.

Here’s why keeping your roof clean should be a top priority:

Extend Its Lifespan: Moss and algae might look harmless, but they can eat away at your shingles.
Prevent Serious Damage: Moss acts like a sponge, holding moisture against your roof. That moisture can cause shingles to curl, crack, or even start leaking.
Save on Cooling Costs: Those black streaks caused by algae? They absorb heat and make your attic hotter, which means your A/C works overtime.
Boost Curb Appeal: A clean roof makes your whole house look better. It’s like an instant facelift for your home.

The Dos and Don’ts of Asphalt Roof Cleaning

Let’s talk ground rules! Cleaning an asphalt roof isn’t rocket science, but you do need to approach it with care. Here’s a cheat sheet of what to do—and what not to do.

The Dos of Asphalt Roof Cleaning

Do Opt for Soft Washing
If you’re picturing a power washer blasting off dirt, think again. High-pressure washing can wreck asphalt shingles by removing their protective granules. Instead, soft washing—a low-pressure method combined with special cleaning solutions—is the gentler (and smarter) choice.
Do Use Eco-Friendly Products
Be kind to the planet (and your garden). Choose biodegradable cleaning solutions that get rid of moss and algae without harming nearby plants or polluting runoff water.
Do Keep Your Roof Debris-Free
A leaf here, a branch there—it all adds up and holds moisture against your roof. Cleaning off debris regularly helps prevent algae and moss from setting up camp.
Do Call in Reinforcements When You Need Them
Some stains or moss patches are just plain stubborn. If your roof looks like it needs extra muscle, a professional cleaning service might be the way to go — they have the equipment and experience to do it safely and effectively.
Do Protect Your Landscaping
Before spraying anything on your roof, cover your shrubs, flowers, and that prized vegetable garden with tarps to keep them safe from runoff.

The Don’ts of Asphalt Roof Cleaning

Don’t Use High-Pressure Washers
Seriously, just don’t. The force can strip away the granules that protect your shingles, leaving your roof vulnerable to damage. No amount of clean is worth that headache.
Don’t Go Overboard with Chemicals
Strong chemicals like chlorine might cut through grime quickly, but they can also degrade your shingles and kill your plants. Stick to gentle, roof-safe products.
Don’t Skimp on Safety
Cleaning a roof is no joke—slippery surfaces, heights, and gravity are a dangerous combo. Wear non-slip shoes, use safety equipment, and know your limits. Better yet, leave it to the pros if you’re not 100% comfortable.
Don’t Wait Until It’s Too Late
Procrastination leads to bigger problems. Regular maintenance, like annual cleaning, helps you catch minor issues before they turn into costly repairs.

How to Clean a Dirty Asphalt Roof: Step-by-Step

Ready to roll up your sleeves? Follow these steps to get your roof looking as good as new.

Inspect the Roof First
Walk around your house and give your roof a once-over. Are there loose shingles? Signs of damage? Avoid walking on sketchy areas—it’s not worth the risk.
Gather Your Gear
You’ll need a soft brush, a garden hose with a spray nozzle, an eco-friendly roof cleaner, and safety essentials like gloves and a sturdy ladder. Non-slip shoes are a must.
Apply the Cleaner
Using a sprayer or soft brush, coat your roof with the cleaning solution. Pay extra attention to spots with algae, moss, or those telltale black streaks. Let the solution sit for about 15–20 minutes (check the product’s instructions).
Rinse Gently
Turn on your garden hose and rinse off the cleaner with low pressure. Avoid spraying directly under the shingles—you don’t want to loosen them. Think “gentle shower,” not “fire hose.”
Tackle Moss and Algae
For stubborn spots, gently scrub with a soft-bristled brush. Emphasis on “gently.” No wire or abrasive brushes, unless you want to accidentally shred your shingles.
Prevent Future Build-Up
Once your roof is sparkling, consider adding a moss and algae treatment. While you’re at it, trim any overhanging branches to let sunlight hit your roof—it’s like kryptonite for algae and moss.

Should You DIY or Hire the Pros?

DIY roof cleaning can save money, but it’s not always a walk in the park. Here are the pros and cons to help you decide:

DIY Roof Cleaning

Pros: Cheaper, more control over the process, flexible timing.
Cons: Risky if you’re inexperienced, limited access to specialized tools, and let’s not forget the workout you’re signing up for.

Professional Roof Cleaning

Pros: Faster, safer, and they know what they’re doing. Plus, no climbing ladders for you!
Cons: Costs more upfront.

When in doubt, weigh the condition of your roof, your comfort level with heights, and how much free time you have. If you’re looking at a roof carpeted in moss, call the pros. Top Dawg Pressure Wash—Abbotsford, BC (778) 539-8948—offers reliable, eco-friendly services to get the job done right.

FAQs About Asphalt Roof Cleaning

What Causes Black Streaks on My Roof?

Those streaks are from algae (specifically Gloeocapsa magma), which loves humid environments and snacks on the limestone in your shingles. Gross, right?

Can I Use a Pressure Washer on Asphalt Shingles?

Nope! Pressure washers are great for driveways, but they’ll destroy your shingles. Stick with soft washing.

How Often Should I Have My Asphalt Roof Cleaned?

Most asphalt roofs benefit from a professional cleaning every 1 to 3 years, depending on your local climate, nearby tree coverage, and how quickly algae or moss tend to grow. Homes in shaded or damp areas may need more frequent cleanings to prevent buildup and preserve shingle integrity.

How Do I Prevent Moss and Algae in the First Place?

Trim back trees to let sunlight hit your roof, keep gutters clear, and consider installing algae-resistant shingles or applying a preventative treatment.

Leave It to the Pros

Let’s face it: while cleaning your roof yourself is possible, it can be risky and time-consuming. If you’d rather skip the hassle, we’re here for you! Our experienced team specializes in safe and eco-friendly asphalt roof cleaning. We’ll handle the heavy lifting and leave your roof looking brand-new.

Ready to revive your roof? Give Top Dawg Pressure Wash – Abbotsford BC a call at (778) 539-8948 to schedule a free consultation or request a quote. Clean roofs, happy homes!

Asphalt Roof Cleaning Tips for a Cleaner, Longer-Lasting Roof

Asphalt Roof Cleaning Tips for a Cleaner, Longer-Lasting Roof

Why Cleaning Your Asphalt Roof Is So Important