The Right Way To Paint a Metal Roof

Metal roofs are a long-lasting, durable solution for homeowners. Modern metal roofs with a factory finish carry a 30-year warranty for fading and chalking. After that, they may need repainting to extend their life and beauty. Consult with your roof’s manufacturer before painting to prevent voiding any warranties.

Older rolled steel and galvanized roofs will require more frequent repainting, as well as rust management, to keep them looking good. If your metal roof is due for some attention, Daniel Haer, owner of DJ’s Painting in Bridgeton, New Jersey, calls repainting it yourself “a good project for homeowners.”

Learn why and how to do it right so your metal roof looks great and withstands the test of time.

Can You Paint a Metal Roof?

Yes. Any type of metal roof can be painted, including outbuilding and house roofs.

How often you need to paint it depends on its age and finish. According to Haer, most buildings today come with a rolled steel metal roof with a Kynar 500 finish, a high-performance weather-resistant coating. Finishes come in various colors for customization, so it’s becoming more popular in residential projects.

These newer roofs shouldn’t need repainting for decades, but color and protection will fade with exposure to ultraviolet rays and weather. At that point, paint renews that protective layer and keeps it looking good longer.

Older metal house roofs without a Kynar 500 or similar finish will need to be repainted every 10 years or so. Whether you paint your roof yourself or hire a pro depends on several factors.

If your roof came with a factory finish and it’s sound, without rust or bare spots, it’s a great candidate for a DIY paint job. Again, if under warranty, consult the manufacturer for recommended products and procedures.

“If you’ve got any rust already started, or you can see any exposed metal that doesn’t have a factory finish, call a pro,” Haer says, “They can properly remove and encapsulate the rust to prevent paint failure.”

If the pitch and height of the roof are low and within your comfort zone, it’s also a good candidate to paint it yourself. “As long as it’s an easily walkable roof, I’d say go for it,” Haer says, “But if the roof has a really steep pitch, that could be dangerous.”

If you feel uncertain or uncomfortable about being on your roof, best to hire a pro with the proper safety equipment and experience.

Painting metal roofs on sheds, garages and other outbuildings is definitely a DIY project due to the safer height and typically low pitch. Silver-colored galvanized metal roofs are good for sheds or outbuildings, and can be painted using the same steps as a rolled steel roof.

How To Paint a Metal Roof

Follow these steps to paint your metal roof the right way.

Consider the weather

For best results, prime and paint on days within your paint manufacturer’s guidelines for temperature and humidity. Look ahead and plan your project for a stretch of clear weather without precipitation. On a sunny day, try to start early to avoid painting on a really hot surface, which can affect paint performance.

Take safety precautions

Before climbing onto your roof, consider several safety protocols, tools and practices. These include:

• Enlist a helper, if possible, to hold the ladder in place and pass up tools.
• Identify any power lines near your home and avoid them when setting up ladders.
• Secure and stabilize the extension ladder properly against your house before climbing up. It should extend three feet beyond the eave.
• Wear sturdy, rubber-soled shoes.
• Wear a roof safety harness connected to a secure point, like a chimney, to prevent falls.
• Don’t work on the roof when it’s wet.

Prepare and clean

Use a pressure washer on a low setting to wash your roof, removing chalky residue, dirt or mold.

For stubborn organic growth, like algae or mold, Haer recommends spraying it with bleach, then rinsing with a low-pressure spray. Protect nearby bushes and landscaping with plastic. Wear eye protection, a face mask and gloves. Also, avoid walking on a wet roof to prevent falls. Allow the surfaces to dry thoroughly before proceeding.

For galvanized roofs, clean with a 1:1 vinegar and water mix to remove the protective coating, then rinse.

Apply primer

For this step, Haer recommends an alkyd oil-based bonding primer. Benjamin Moore’s SuperSpec HP Alkyd Metal Primer is a great product with excellent adhesion. Apply primer with a paint sprayer or extended roller and brush, starting at the peak and working down toward your ladder. Follow the manufacturer’s dry time before painting.

For galvanized metal roofs, use an acrylic metal primer, like Benjamin Moore’s UltraSpec HP Acrylic Metal Primer.

Apply paint

For rolled steel roofs, Haer suggests a high-quality exterior acrylic paint like Sherwin-Williams’ Superpaint or Benjamin Moore’s Regal. You can also use a direct-to-metal (DTM) paint like Benjamin Moore’s UltraSpec, but make sure to use an alkyd bonding primer underneath.

“We learned the hard way that if you put DTM paint directly on a roof surface, a lot of times it doesn’t bond properly,” Haer says, “So always start with an alkyd oil-based primer.”

Apply paint the same way as the primer, in the same order. Follow the paint manufacturer’s recommendation for dry and re-coat times.

For galvanized roofs, try Valspar’s Metal Building Siding and Roof Finish, an acrylic paint meant for metal roofs on outbuildings, barns and sheds.

About the Expert

Daniel Haer is the owner of DJ’s Painting in Bridgeton, New Jersey, a full-service company that provides commercial, industrial and residential painting services. In the 2000s, his company began painting the roofs of national chain locations in all 50 states for clients like McDonald’s, Walmart, The Home Depot and Walgreens.