Since the middle of the 20th century, metal has been a popular material for commercial and agricultural buildings for its durability, quick construction, and cost-efficiency. Not only do metal buildings have many logistical advantages over other materials, but painted metal buildings have a sleek and often bold style that can be hard to compete with.
Before you begin a painting project for your commercial metal building, however, there are a few things that are crucial to know, including perhaps the most essential factor of any painting project: the best paint for metal buildings.
Why Paint a Metal Building?
Unlike some popular representations, metal is not exclusively used for warehouses, pole barns, or garages. More and more, people are opting to include metal in their commercial buildings, including restaurants, corporate office buildings, and small businesses. These metal buildings should be painted not only to give them a unique aesthetic that matches the business they host but also to keep the buildings in their best condition for years to come.
Adding a coat of paint to a steel or aluminum building will seal the surface and prevent rust, which is one of the biggest issues that one may encounter with a metal building. Eliminating the possibility of rust spots on a metal building will improve its longevity and durability. An extra coat of paint can serve as an additional layer of protection against the elements, including threats of corrosion and rust.
How to Prepare Metal Buildings for Paint
It is crucial to understand that painting a metal building takes much more than just the painting itself. Since the point of painting a metal building is to seal the building off from any debris or corrosive materials, you need to make sure that all of those materials have been effectively removed from the building’s surface—otherwise, everything will be sealed in between the paint and the metal surface. Here are the surface preparation steps you should follow to ensure that your paint is on a truly blank canvas.
Remove Rust from the Surface
Check the exterior or metal siding of your building for any rust spots, keeping an eye out specifically for rusted screw heads. If any screw heads have rusted over, replace them with new screws—this will be easier than removing the rust from the existing screws and are less likely to impact the structural integrity of the building. Use a wire brush or fine-grit sandpaper, which is most effective when attached to a belt or orbital sander, to remove the rust from the surface without damaging the surface itself.
Remove Dirt from the Surface
Once the rust has been removed, you’ll need to clean the surface of the building from any natural dirt and debris that has accumulated on it, as well as remove any previous coatings of paint. The best way to do this is to use a power washer and a solution of phosphate-free laundry detergent (or a cleaning solution specifically made for cleaning metal) and water, with a ratio of one fourth cup of cleaner to each gallon of water. When washing the surface, be sure to use only enough soap for one side at a time, as you don’t want any soap to dry on the building. Start the pressure washer at the top of each side of the building and work your way down each side, so that you need to make as few passes over each side as possible.
Apply Primer
Even though certain paints boast that they don’t need primer before their application, it’s always best practice to apply a rust-preventative primer to your building before applying any paint. This is especially true for when you use an acrylic-based paint, which allows moisture to reach the surface. Using an airless sprayer, apply the primer all over the building’s surface, not just where you found rust earlier.
Tape Off the Work Area
Just as in any form of painting, make sure that you tape or mask any areas of the building that you do not plan to paint. This may include windows, doorways, electrical outlets, or trim.
How to Paint Metal Buildings
Painting a metal building is similar to painting any exterior building. However, there are a few things to keep in mind to make the process as easy as possible.
To get the smoothest application and cover the largest surface area at once, we recommend using an airless paint sprayer on your metal building. This will not only speed up the process, but it will make it easier to maintain a wet edge while painting, which will prevent any differences in color intensity and sheen in the overlapping paint areas. Furthermore, you should retain a consistent distance from the building during the entire process to avoid inconsistencies in the paint application and any runniness that arises from the wet edge. If there is any runniness, use a brush to smooth out the dripping paint.
Finally, remove the tape and masking from the building immediately after you have finished painting, before the paint dries. This ensures that the paint will not peel off along with the tape.
Comparing the Best Paints for Metal Buildings
Now that you understand how to prepare and paint your metal building, it’s crucial to understand which of the many offerings on the market is the best paint for metal. Using high-quality paint will improve the bond that the paint makes with the metal surface, which will in turn strengthen the paint’s purpose as a protective coating. Below, we explain some of the advantages and disadvantages of each of the metal paints on the market.
Direct-to-Metal (DTM) Paint
Direct-to-Metal (DTM) paint, which can be water or solvent-based, is specifically formulated for use on metal surfaces. DTM comes in both interior and exterior paint formulas, and its biggest advantage is that it claims to work as both paint and primer in one. However, some claim that the dual nature of this kind of paint leads to lower performance in corrosion prevention and UV-resistance.
Oil-Based Paint
There are many different claims about oil-based paint online, and they often contradict one another. Many resources state that oil paint adheres to metal surfaces better than other kinds of paint, while others claim that because of its resistance to water, oil paint is unable to create strong adhesive bonds with the surface. The most important thing to note about oil-based paint, however, is that its resistance to moisture makes it naturally rust-resistant, as it is less likely to let moisture reach the metal surface.
Acrylic Latex Paint
Much like with oil-based paint, there are many different sources online that define acrylic latex paint differently. Oftentimes, acrylic latex paint is conflated with acrylic paint, because both are made with acrylic resin (and latex paint does not actually have latex in it). Importantly, acrylic latex paint is one of the best paints for outdoor usage and in places with extreme weather differences because of its flexibility and resistance to cracking. Because this kind of paint absorbs moisture, it is crucial to use a primer on to-be-painted surfaces to prevent rusting.
Commercial Metal Building Painters in Houston
Now that you know more about the best paint for metal buildings, you can begin planning your next metal building painting project. As shown from the multiple steps and considerations, painting a commercial metal building is a long and sometimes difficult process, but you need not worry about doing it alone. Professional painting services can talk with you about your paint options and do all the dirty work for you, from sanding away rust to painting the hardest-to-reach spots of metal roofs.
For over 20 years, Pro Painters has been painting residential and commercial buildings in the greater Houston area using only the highest quality materials in addition to expert craftsmanship. We take such pride in our work that we offer a five-year guarantee on all residential work and a one-year guarantee on all commercial work we perform. Contact us today for a free quote and consultation—no project is too big or small for us.
