Is Roof Washing Bad for Your Roof? What You Should Know

By Top Dawg Pressure Wash Blog 0 Comments

It’s a common worry: you look at your roof, see moss, algae, or unsightly streaks, and wonder, “Should I clean it? Won’t that damage it?” For many homeowners, this question stops them from taking action—and it’s often because of the myth that roof washing causes more harm than good.

But here’s the truth: when done the right way, roof cleaning doesn’t just make your home look better—it helps your roof last longer.

In this article, we’ll break down the misconceptions, explain what roof washing really involves, and help you understand why it’s not only safe—it’s essential.

The Root of the Concern: Confusing Pressure Washing with Soft Washing

The biggest source of confusion comes from the assumption that roof cleaning = pressure washing.

Pressure washing is aggressive. It’s great for sidewalks, driveways, and some siding, but not for roofing materials—especially asphalt shingles. Using high-pressure water on your roof can:

Strip away the protective granules that keep shingles weatherproof
Force water underneath the shingles, leading to leaks and rot
Void your roof’s manufacturer warranty

So yes—pressure washing your roof can be very bad for it. But here’s the thing: that’s not what professional roof cleaning companies like Top Dawg Pressure Wash do.

We use soft washing, a completely different method designed to clean thoroughly without causing damage.

What Is Soft Washing?

Soft washing is the industry-standard method for roof cleaning. It uses low-pressure water (no stronger than a garden hose) and a specially formulated cleaning solution—usually chlorine-based—to treat and eliminate organic growth like moss, algae, and lichen.

Here’s how it works:

Application: The cleaning solution is gently sprayed across the roof’s surface.
Dwell Time: The solution is left to soak in, killing moss and algae all the way to the root.
Natural Breakdown: Over time, the dead moss detaches and washes away naturally with rain.

Unlike pressure washing, soft washing doesn’t blast anything off your roof—it treats the problem at the source and gives your roof time to clear on its own.

How Long Does It Take to See Results?

This surprises some homeowners: the roof won’t be spotless the next day.

While soft washing starts working immediately, you’ll typically see full visual results in about 6 to 8 weeks. That’s how long it takes for the moss to dry out, loosen, and fall off naturally. This gradual process is intentional—it avoids damage and lets nature do the rest.

In cases where thick moss is present, we may brush select areas to improve the appearance—but with extreme care. As always, the team at Top Dawg Pressure Wash, ensures each job is handled with precision and caution. You can reach us at (778) 539-8948 for expert service.

What About Brushing? Won’t That Ruin My Shingles?

It’s a fair question. Asphalt shingles have protective granules that help shield against UV rays and extend the roof’s lifespan. If you brush too aggressively, it can indeed knock those granules off.

That’s why we don’t brush everything.

Here’s our brushing policy:

We only brush moss that’s larger than a credit card.
We use soft-bristled brushes and gentle strokes—never aggressive scrubbing.
Brushing is simply cosmetic—it helps you see results faster, but the real cleaning is done by the solution.

And here’s something most homeowners don’t think about: where you step matters just as much as how you clean.

Our team is trained to move across roofs safely—avoiding fragile areas like ridge caps and walking only where it’s structurally secure. Improper foot placement can crack tiles or wear down shingles. That’s why professional experience matters.

Common Myths About Roof Cleaning—Debunked

Let’s run through some of the most common misconceptions we hear from customers:

Myth 1: Chemicals will ruin my roof.

Not true. We use a chlorine-based soft wash solution that’s formulated specifically for roofing materials. It’s strong enough to kill moss at the root but safe when applied correctly.

We also rinse thoroughly and protect surrounding landscaping to avoid runoff damage.

Myth 2: If moss grows back, the treatment didn’t work.

Moss can return over time, especially in shaded, damp areas. But at Top Dawg, we stand behind our service with a 2-year moss-free warranty. If anything returns during that period, we’ll take care of it—no hassle, no extra charge.

Myth 3: My roof looks fine, so I don’t need to clean it.

Even if your roof looks okay, early-stage moss and algae may be developing where you can’t see them—like near flashing, under debris, or on the north-facing side of your roof. Waiting until it’s visible often means the damage has already started.

Why Roof Washing Helps Your Roof Last Longer

Let’s look at the benefits from a more practical angle. When you clean your roof using proper soft washing methods, you:

Prevent damage: Moss holds moisture against your roof, leading to wood rot, leaks, and structural issues over time.
Avoid premature replacement: Regular cleaning extends the life of your shingles, delaying costly roof replacements.
Save on energy bills: Algae streaks trap heat, making your attic warmer and your cooling system work harder. A clean roof reflects more sunlight.
Improve curb appeal: A mossy, streaked roof makes your whole house look older. Cleaning restores a fresh, well-maintained appearance.

And since we back every cleaning with a 2-year moss-free warranty, you get long-lasting peace of mind.

Should You Clean Your Roof Yourself?

Short answer? Probably not.

Here’s why:

Safety risks: Roofs are high, steep, and slippery—especially when wet. Falls are one of the top causes of serious home-related injuries.
Improper technique: Using a pressure washer or the wrong cleaner could do real damage. We’ve seen it happen time and again.
Missed spots: DIY attempts often fail to treat moss at the root, which means it grows back faster.

Professional roof cleaners bring the right tools, training, and safety equipment. Our team knows how to navigate the roof, apply the treatment thoroughly, and leave your property clean and protected.

FAQs

How often should I wash my roof?

Every 1 to 3 years depending on your environment. Shady or damp areas may require more frequent attention.

Can I use a garden hose and soap instead?

That might help with light dirt, but it won’t treat the moss or algae at the root. Soft washing uses specific chemistry to do the job properly.

Will the cleaning damage my plants?

We take care to wet down surrounding vegetation before and after applying the solution and use protective coverings when needed.

Is your service insured and guaranteed?

Absolutely. We’re fully insured, and all roof cleanings come with a 2-year moss-free warranty.

Final Thoughts

So—is roof washing bad for your roof? Only if you do it wrong.

When done using safe soft washing techniques by trained professionals, roof cleaning is not only safe—it’s one of the best things you can do for your home. It protects your shingles, boosts your curb appeal, and prevents costly repairs.

At Top Dawg Pressure Wash, we specialize in roof care that’s effective, safe, and guaranteed. With years of local experience and a dedicated, trained crew, we’re here to help you get the most out of your roof. Call us today at (778) 539-8948 to schedule your service and get expert care that lasts.

Your roof—and your wallet—will thank you.

Is Roof Washing Bad for Your Roof? What You Should Know