Cleaning a Metal Roof | 2024 Guide
Metal roofs are popular because they’re durable, have a sleek appearance, and require little maintenance. Homeowners should still clean them now and again to remove buildups of dirt, debris, mold, and other particles that can lead to premature deterioration.
Our guide offers tips on how to clean a metal roof safely and effectively with products such as mild laundry detergent and mild dish soap. We’ll also help you decide whether to clean your roof as part of a do-it-yourself project or call a professional roof cleaning service.
Compare Quotes from Roofing Specialists
Just answer a few questions, and we'll take care of the rest.
Metal Roof
Metal roofs cost, on average, between $7,081 and $110,150.
Tile Roof
The NRCIA reports that the average tile roof cost is $8,000 to $23,000.
Shingle Roof
Shingle-style roofs cost, on average, $5,000 to $18,000.
Why Does a Metal Roof Need to be Cleaned?
Your metal roof is an investment that plays an important role in protecting your home. Metal roofs typically require less maintenance than other roof types, such as asphalt shingles, but they still need occasional cleaning.
Clearing your metal roof of dirt, leaves, and twigs immediately boosts your home’s curb appeal. Periodic cleaning also removes particles and pollutants that could degrade the paint or substrate of your roof’s metal panels. Your clean roof will improve your home’s appearance, extend its life span, and improve your home’s value.
Best Metal Roof Cleaning Tools
Metal roofing requires very specific cleaning tools. The material is durable, but the roof’s finish is susceptible to damage from sharp or abrasive objects. Gather the following tools and materials before getting started.
- Eye protection: Protect your eyes from flying debris, detergent, or chemical droplets.
- Fall protection system: Use a fall protection harness or other safety device as directed by the manufacturer.
- Garden hose: A pressure washer can damage or dent your roof. Use a garden hose instead.
- Ladder: Use a high-quality Occupational Safety and Health Administration-approved ladder for climbing up to your roof.
- Non-abrasive cleaning pad: Use a cleaning pad with a soft surface to scrub away stubborn dirt.
- Neoprene or nitrile gloves: Use chemical-resistant gloves to protect your hands while using solvents and chemicals.
- Supportive shoes with good traction: Shoes that fit well and have good traction will help you to avoid slipping on your roof’s slick surface.
- Soft bristle brush: Use a brush with very soft bristles to scrub stuck-on substances or rust spots.
- Sponge: Use soft sponges to clean away dirt and grime.
- Washcloth: Use washcloths to gently clean with plain water or gentle detergents.
Best Metal Roof Cleaning Products
Metal roofs typically feature sealants, coatings, or paint that protect them against the elements. The best metal roof cleaning products are gentle enough to avoid damaging these protective coatings. Consider the following cleaning products:
Plain Water
Once you’ve removed large debris from your roof, use a hose to spray plain water onto your roof to wash away dust, dirt, and other items that aren’t stuck to your roof’s surface.
Detergents
Apply detergent solutions to your roof with a sponge or washcloth, and let them sit for five to 10 minutes. Do not let the solutions stay on long enough to dry on the roof’s surface.
The most common solution for cleaning metal roofs is a combination of dish soap, laundry detergent, or car washing soap mixed with water. You can use one of the following detergents mixed in a solution of 1/4 cup detergent to 1 gallon of water.
- Mild dish detergent, such as Dawn or Ivory
- Simple Green or other non-toxic biodegradable cleaners
- Spic-N-Span laundry detergent
Solvents and Petroleum Solvents
Use solvents only in moderation on your roof to remove tough elements, such as grease, oil, paint, or tar. Test solvents before you use them.
Always follow the manufacturer’s instructions, and wear eye protection and gloves when using solvents. Keep your work area properly ventilated, and keep products away from open flames.
Try these products in small amounts as needed for removing tough, non-water elements.
- Mineral spirits
- Rubbing alcohol
- Turpentine (wood or gum spirits)
- VM&P Naphtha
Special Metal Roof Cleaning Circumstances
As your roof ages and encounters lots of moisture, it may require a cleaning solution that’s stronger than a mild detergent solution. Read more about how to clean older roofs below.
Removing Mildew, Algae, or Mold on Metal Roofing
Homes in humid climates are more susceptible to mildew and mold growth on metal roofs. Cleaning stubborn mold and mildew requires a tougher cleaner and a full rinse. Take the following steps to remove mold and mildew.
- Mix a cleaning solution of 1/3 cup of powdered laundry detergent, a quart of bleach, and 3 quarts of water.
- Apply the cleaner to affected areas with a soft bristle brush or cloth.
- Lightly scrub the surface until you’ve eradicated mold and mildew.
- Rinse the clean surface well with plain water.
Removing Rust Stains on Metal Roofing
Early rust stains are often a result of stuck-on particles or grime. You can remove these rust-colored stains with a 5:1 solution of water and acid. Wear Neoprene or Nitrile gloves when working with acids. Begin by mixing 5 parts water with 1 part of one of the following acids.
- Citric acid
- Hydrochloric acid
- Muriatic acid
- Oxalic acid
- Vinegar
Use a cloth to apply the solution to affected spots, and clean away rust stains with circular motions. Leave the solution on the surface for no more than five minutes, then rinse immediately. Repeat the process on all rust stains. If the rust doesn’t rinse away, call a professional.
The most common contributors to rusting include excess moisture, high salt content in the air, inadequate maintenance, and lack of protective coating. Routine maintenance is the most effective way to prevent the early rusting of your metal roof.
Metal Roof Cleaning Considerations to Remember
Cleaning your metal roof requires special considerations to stay safe and avoid damage to your roof. Follow the tips below for a successful cleaning project.
- Avoid using a pressure washer. The force of a pressure washer can damage the roof’s protective coating, create dents, or drive the roof’s seams apart. It can also void your roof’s warranty.
- Choose a dry, overcast day for cleaning your metal roof: Rainy days can make your roof’s surface more slippery and increase the potential for accidents. Bright sunny days make the metal very hot, and the reflective surface impairs visibility.
- Don’t overuse cleaning products: Concentrating a solution too much, or mixing chemicals, can damage your roofing materials. Leaving a solution on the roof too long can also harm the paint or sealant that protect your roof panels.
- Learn which products are safe for use on metal roofing: Corrosive and abrasive cleaners can ruin the finish on your metal roof panels and cause early deterioration. Contact a roofing professional for advice if you’re not sure about certain cleaning products.
- Prioritize safety: Use a sturdy ladder, a fall protection system, and shoes with good traction when working on your roof. Always have the company of at least one other person in the area when climbing on a roof.
- Try out cleaning solutions before using them: Test your cleaning solution on a small spot to make sure it doesn’t cause any damage.
- Use touch-up paint to repair imperfections: Windblown branches or twigs can scratch the coating on your roof. Repairing these spots with touch-up paint can help you extend your roof’s protective surface. Make sure the products you purchase are safe for metal roofs, and follow the manufacturer’s instructions while using.
Our Recommendation
Cleaning your metal roof is a part of routine maintenance that can extend your roof’s life span and improve your property’s curb appeal. It’s a job you might be able to complete yourself, but only if you follow proper safety protocol. Consider hiring a professional roofer if you’re not sure about your abilities. Use gentle cleaning solutions and non-abrasive tools to keep your roof looking brand new for years to come.
Compare Quotes from Roofing Specialists
Just answer a few questions, and we'll take care of the rest.
Cleaning a Metal Roof FAQ
What is the best thing to clean a metal roof with?
The best thing to clean a metal roof with is plain water. If grime persists, use a solution of mild detergent and water.
Is it OK to pressure wash a metal roof?
It is not OK to pressure wash a metal roof. The high pressure of a power washer can dent the metal, damage the roof’s protective coating, and drive the roof’s seams apart. Using a pressure washer may also void your roof’s warranty.
How do you remove mold and mildew from a metal roof?
You can remove mold and mildew from a metal roof with a solution of 1/3 cup of powdered laundry detergent, 1 quart of bleach, and 3 quarts of water. Make sure to rinse the area thoroughly after cleaning.
Does Wet & Forget work on metal roofs?
Wet & Forget cleaning product works well on metal roofs. However, make sure that the active ingredient, alkyl dimethyl benzyl ammonium chloride, is safe for your roof and won’t void your warranty.
When should I hire a professional to clean my metal roof?
You should hire a professional to clean your metal roof if you don’t think you can complete the job yourself. If you’re unable to safely climb a ladder, don’t have the right equipment, or feel uncomfortable working on a roof, call a professional.
