If you need a new roof and are considering a metal variety, you may wonder whether metal roofing rusts or fades over time. While metal roofing may be the most durable and affordable material for your roofing over other options, we’ve found some important details about the longevity of metal roofing in terms of rusting and fading.
All types of metal have the potential to rust, but modern metal roofing is typically coated with a protective layer to prevent rusting as long as possible. Metal roofs will fade over time, no matter the type of paint or resin used to cover them.
What causes metal roofs to fade? Can you prevent your metal roof from rusting with special paint? Is it better if you paint your roof instead of leaving it bare? Keep reading for a comprehensive exploration of various metals and paints that rust and fade in color and what to do about it.
Modern Metal Roofing And Rust
Rusting or corrosion occurs when oxygen and moisture mix together on metal. Dryer climates withstand rusting for longer periods of time, but even dry climates experience rain and moisture. On the other hand, rainy climates or regions near large bodies of water should expect a larger amount of rust over time.
All metal rusts eventually, but some materials rust more gracefully than others. In regard to roofing, manufacturers now produce metal sheets with a protective layer in order to prevent rust. The two most common types of protective layering are galvalume and galvanized steel.
Galvalume sheets consist of steel dipped into a solution made up of aluminum, zinc, and silicone. This conglomerate of metals provides a protective material that withstands rusting for the longest amount of time. However, galvalume tends to show more scratches, and if the protective layering is scratched away, it will rust in those places.
Galvanized steel also utilizes a protective layering, but it only contains zinc. While zinc effectively prevents rust over time, it performs better when combined with aluminum and silicone, as in galvalume steel. Unlike galvalume, galvanized steel does not scratch as easily.
Other Types Of Metal Roofing
Older roofing most likely never underwent a coating process, so it often rusts much more quickly than newer roofing with protective layering. Even so, some uncoated metals never accumulate an ugly rusted look, even though they do rust with time.
Optimal uncoated metals for roofing:
- Aluminum produces white rust instead of red, so the rust appears less visible, especially when painted white. It also naturally takes longer to rust than other types.
- Stainless Steel contains a certain amount of chromium, which makes the metal extremely resistant to oxidation.
- Zinc, the metal used in the galvalume and galvanized processes, forms a protective layering for itself as a patina, which does not show like red rust.
- Copper forms a patina in a wide range of colors. While some people prefer to avoid this process, many more people seek copper roofs specifically for the colors produced by patina.
Why Do Metal Roofs Fade?
Depending on where your home is located, you may face a range of different factors that cause your metal roof to fade. The most common factors include:
- Sun exposure
- Extreme fluctuations in temperature year-round
- Rain, humidity, and moisture
- High amounts of pollutants in the air
Manufacturers test different types of paints in a wide range of climates and conditions in order to provide the most optimal formula for your location. However, no matter your region, tests have shown that the best way to prepare for fading is to use an inorganic, neutral-toned paint that contains a resin. This type of paint normally must be bought from Sherwin Williams or Valspar because they contain a patented substance called Kynar 500.
How Do I Keep My Metal Roof From Rusting?
To prevent rusting for the longest amount of time, consider installing galvalume or galvanized steel. Even with these specially coated panels, you need to maintain your roofing every 5-10 years in order to prevent rusting.
A great way to not only prevent rust but also prevent leaks is to use an elastomeric coating. This special coating is much thicker than regular paint. Due to its coverage and protection, you can purchase this special coating in different colors in place of painting your roof.
Gardner Metal Roof Coating
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If rust has already formed on your roof, you need to clean, scrape, and coat/paint your roof. You can use a great multi-purpose metal polish/cleaner.
Brasso
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For scraping the rust away from your roof, opt for a wire brush with a long handle.
Heavy Duty Wire Brush
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Finally, re-coat or paint your roof with the elastomeric coating or with a rust-resistant paint. If the rust refuses to budge no matter how much you wash or scrub it, consider purchasing a paint specifically for rusted metal.
Rust-Oleum Primer
This Rust-Oleum paint adheres to the rusted metal and helps prevent further corrosion.
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How Do You Keep Your Copper Roof From Turning Green?
The best and most effective way to prevent your copper roof from turning green is to clean it regularly. A home remedy that works well for copper is a mixture of lemon juice and salt. If the stain requires more elbow-grease, add some white vinegar to the solution to make it easier to remove.
Again, as mentioned above, Brasso provides an extremely effective clean and shine for any type of metal roof if you choose not to use the home-remedy solution.
Use a long-handled normal brush to clean away debris and dust before spraying and wiping with your choice of cleaner.
48-Inch Roof Brush
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For a beautiful vintage look, consider letting your copper roof turn green for a sought-after patina finish. Many people pay professionals to purposely turn their copper roof green with an aging process to achieve this vintage style.
Do Metal Roofs Need To Be Painted?
Metal roofs do not need to be painted, especially if they are galvanized/galvalume or made of a metal that looks natural when it rusts or develops a patina. Also, instead of paint, you may choose to use a special coating. The coating can be clear or tinted like paint.
With that being said, painting your metal roof holds many benefits:
- Prolongs the lifetime of the metal
- Makes it more energy efficient
- Prevents leaks
- Gives a unique finish to your home
Painted metal roofing requires maintenance every 10 years in most climates. Most paint can be brushed, rolled, or sprayed onto the roof. Before applying paint, consider using a sealant to add protection from leakage.
For double protection, use a rust-resistant primer before painting. You can also apply a rubber coating for additional leak protection.
Rust-Oleum Regal Red
For a classic red or a bold color for your business, opt for this color.
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Make sure to prepare for painting your roof with the right tools, including protective gear (masks, gloves, glasses) and your applicator of choice (brush, roller, sprayer).
Heavy-Duty Brush Set
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What Is The Best Color For A Metal Roof?
For hotter regions, it’s best to opt for a lighter color of paint in order to reflect the sun away from the home. Choosing a lighter tone of paint reduces your energy bill and helps keep the home at an optimal temperature. Not only that, but lighter colors help make a home look bigger and more spacious.
If you live in a colder climate or in one without much direct sunlight, opt for a darker color of paint. The darker tone will draw the sun to it and help keep the home warmer. Darker tones draw attention to your home and create contrast with a lighter siding color. It also tends to create a more classic style.
If you live on the beach or in a coastal town, take advantage of the light and airy styles of beach homes by choosing a bright color for your metal roof. Not only will it reflect the cheerful beach style, but it will also help hide and prevent rust that can form more easily in coastal climates.
In Closing
With this comprehensive guide, you now have the information you need to purchase the perfect metal roofing for your climate. With the right type of metal, coating, and/or paint, you can prevent rusting and fading for years to come.
Even with the best coated metal roofing, expect to maintain your roof every 5-10 years for rust-resistance, leak-proofing, and energy efficiency.