How to Safely Clean Moss Off an Asphalt Shingle Roof

Moss might give your roof a charming, forest-cabin look, but don’t be fooled. If you have moss growing on your asphalt shingle roof, it’s doing more harm than good. Moss holds moisture against your shingles, which can lead to premature deterioration, leaks, and costly repairs. But before you grab a pressure washer or harsh chemicals, read this guide to learn how to clean moss off your asphalt roof safely and effectively.

Why Moss Is Bad for Asphalt Shingles

Moss spreads quickly in damp, shaded environments, especially in areas like Vancouver. It creeps under shingles, lifts them up, and traps moisture that can cause rot or mold. If left unchecked, moss can shorten your roof’s lifespan significantly.

What Not to Do

Before we get into the right method, here’s what you should not do:

Don’t scrub aggressively with wire brushes — this causes more damage than it removes.
Don’t use straight bleach — it’s corrosive, harmful to plants, and can damage your shingles.

Safe Way to Remove Moss from Asphalt Shingles

If you’re planning to clean moss off your asphalt shingle roof yourself, the first priority should always be safety. Use a sturdy ladder, wear non-slip footwear, and never attempt the job alone. If your roof is steep or has multiple levels, it’s safer to hire a professional.

Once you’re ready, start by gently removing large patches of moss with a soft-bristle brush or broom. Be sure to brush downward in the direction of the shingles to avoid lifting or damaging them. Next, apply a moss-killing solution, either a store-bought treatment designed for roofs or a homemade mix of 50/50 water and white vinegar. Spray it evenly over the affected areas and let it soak for 15 to 20 minutes.

After the solution has had time to work, rinse the roof gently using a garden hose with a spray nozzle. Avoid any high-pressure equipment, which could harm the shingles. Finally, don’t forget to clean your gutters. Moss and debris often wash down and can clog the system, so clearing them out ensures proper drainage and helps prevent moss from growing back.

Preventing Moss from Coming Back

Trim back overhanging branches to let more sunlight reach your roof.
Keep your roof and gutters clear of leaves and debris.
Consider installing zinc or copper strips near the ridge; rainwater will carry these minerals down the roof, which helps inhibit moss growth.
Schedule regular roof cleanings—especially in high-moisture areas like the Lower Mainland.

Should You Hire a Pro?

If you’re dealing with heavy moss buildup, a steep roof, or want long-lasting results, professional roof cleaners like us are your best bet. We use low-pressure soft washing techniques and safe, effective cleaning solutions that won’t damage your asphalt shingles.

Moss may seem harmless, but on an asphalt shingle roof, it’s a warning sign. Cleaning it properly protects your roof, improves curb appeal, and helps you avoid costly repairs. Whether you do it yourself or call in a pro, stay gentle, stay safe, and don’t wait too long.

Need help? Contact us, your local roof cleaning service and get rid of moss the right way.