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3 Tips to Clean a DECRA Metal Roof From Algae, Lichen, and Mold

Trevor Underwood • January 4, 2021

3 Tips to Clean a DECRA Metal Roof From Algae, Lichen, and Mold


Due to the inevitable accumulation of dust and dirt, metal roofs may attract algae, lichen, and mold over time. Other factors, such as your home’s proximity to overhead trees, as well as the presence or absence of sunlight, may also bring other pollutants to metal surfaces that could affect the cleanliness of your roof. This may surface common questions like “How do I clean a stone-coated metal roof?” or other queries related to the product or home care instructions. 

As a leader in our industry, DECRA Metal Roofing understands the challenges our customers face when learning how to clean a roof for the first time. Luckily, stone-coated metal roofing offers homeowners the opportunity to take practical measures to clean, care, and restore their roofing back to its original appearance by carefully considering the following practices when removing pollutants from your home. 

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1. Take Safety Precautions

Your safety should always be the first priority during any home improvement project, so we encourage all of our customers to take the proper precautions before cleaning a stone-coated metal roof

This includes using fall safety measures, such as ladders or scaffolds for entering or exiting the roof to prevent hazards. Additionally, avoid no stepping zones on the roof for your safety. 

You’ll also want to make sure you disconnect your roof cistern collection systems to avoid contamination when cleaning your roof. Allow the roof to flush at least three rainfall occurrences before reconnecting roof water run-off back into the cistern collection system.

2. Avoid Harsh Water Pressures

While DECRA stone-coated metal roofing can withstand even the harshest weather conditions, you’ll still want to avoid forceful pressure washers to prevent affecting its appearance accidentally. For soft wash roof cleaning, do not use water pressure above 500 pound-force per square inch (PSI). Instead, carefully spray water as a soft rinse procedure rather than a removal method for algae, lichen, mildew, moss and more. A garden hose will also do. 

Additionally, you also don’t want to exceed 160 degrees (F) water/solution temperature if using heated water or steam cleaning apparatus. 

3. Use the Right Products

Next, we advise customers with stone-coated metal roofing to use the right products for cleaning. It’s a common misconception that copper or iron-based products or solutions can treat roofs for algae, lichen and moss growth, but we don’t recommend using those because they can damage a roof. 

In fact, copper-based products accelerate corrosion to roof panels, due to dissimilar metal galvanic reaction. As for iron-based products, they rust stain your roof

So, which cleaning products should you use on a roof? Like any cleaning product, follow the preparation and application instructions on the back of a bottle to protect the areas you're cleaning. If you need a recommendation, the following list of cleaners are compatible and safe options we recommend using on roofing materials: 

Tip: Metal Roofs are Really Easy to Clean

Simply mix the cleaning products listed above with a gallon of water and a quart of bleach for the best results. Make sure to mix these items really well before applying them to your roof. Then, spray the mixture on your roof and let it sit for about 15 minutes. 

More steps you can take to keep your metal roof clean: 

  • Trim any tree branches that impede the roof or block sunlight. 
  • Clear debris on top of the roof. 
  • Clean your gutters to prevent build-up of leaves and/or branches. 

How to Clean Metal vs. Asphalt Roofing

If you’re researching new roofing and trying to decide between stone-coated metal or asphalt options, consider the practical benefits of owning a metal roof. Metal roofing is not only easy to clean, but it’s effortless to care for compared to asphalt or tile, which can break or rise when exposed to pollutants. What’s more? DECRA products last 2-3 times longer than conventional roofing materials, making them an investment that pays for itself while being easy to maintain.

Contact DECRA Metal Roofing for Assistance 

DECRA is the original manufacturer of the stone-coated metal roof. Our state of the art products are lab tested to withstand the harshest elements to ensure longevity and always include our innovative limited lifetime warranty as added protection. 

Need roof cleaning assistance? Contact us with questions or concerns about your roof. Our metal roofing advisors can help you take the proper precautions to prevent algae and moss build up.