As an architect, you’re a decision maker. Designing a building comes with the responsibility that each choice made throughout the design process can affect how the final product will look and perform. With so many offerings at your fingertips, how do you know which metal coating will be the right fit for a project?
Photo: Liam Frederick
Start by Knowing Your Options
When it comes to coating metal, two options are at the forefront: pre-painted (coil) and post-painted (extrusion). Coil coatings are applied to coil-formed metal sheets by a continuous, automated process that can happen at up to 700 feet per minute. Coil is unwound, cleaned, treated, primed, painted and baked before being recoiled for shipment. Coil coated products can be used not only for building exteriors such as roofing and panels, but also for a variety of interior finish applications including walls and ceilings.
Another option is the extrusion coating process. Also referred to as post-paint, this manufacturing process occurs on a vertical or horizontal line that consists of cleaning and pretreating aluminum preformed extrusions, through a spray process, and then thermally curing the coating to set the system. Extrusion coating is often used for skylights and window trims, as well as curtainwalls and entry canopies.
Both pre-paint and post-paint have similar benefits, which include being sustainable, durable and offering a wide variety of colors, finishes and special effects. Factory-applied coatings provide excellent protection whether they are applied before or after the part is formed. And there are many formulations available depending on the specific need.
Factors to Consider When Specifying Metal Coatings
Architects and designers can begin by finding a trustworthy coatings partner that is constantly developing new formulations that deliver beauty and long-term performance.
There are a lot of things to consider before selecting a coating that’s right for your project. To ensure you’re receiving your desired performance and appearance, follow these steps. Don’t be afraid to ask questions.
1. Location and climate
Beyond the aesthetics and type of building, it’s also critical to consider where it will sit. Exposure to the sun (UV light), moisture, humidity, high temperatures and temperature fluctuations can lead to color changes, chalking, blistering, corrosion and many other physical factors that can affect the performance and protection of the metal coating. If you’re designing a building for the coast or shoreline, it’s important to consider coatings that protect against corrosion.
For climates with heavy sun exposure, you’ll want to look for coatings with strong resin types to reduce risk of fading and chalking. Resins are what bind together all the components of a paint formulation and increase the physical strength and chemical resistance of coating film. The stronger the resin bond, the more the coating will look like new.
Facilities in sunny climates may also be suitable for coating applications with solar-reflective pigments. These solutions can help reduce heat absorption, reduce sun exposure indoors and ultimately lower facility energy costs without sacrificing the durability or beauty of the building.
When it comes to coating metal, two options are at the forefront: pre-painted (coil) and post-painted (extrusion). Coil coated products can be used not only for building exteriors such as roofing and panels, but also for a variety of interior finish applications including walls and ceilings. Extrusion coating is often used for skylights and window trims, as well as curtainwalls and entry canopies.
2. Project sustainability requirements
Are you looking for the project to follow sustainability guidelines, such as LEEDv4 or Living Building Challenge? More and more architects are looking for longterm solutions that not only aid the environment today, but will also meet sustainability standards of the future. For instance, although not currently regulated in the U.S., the International Future Living Institute (ILFI), the Green Building Council (GBC) along with their industry partners have succeeded in standardizing requirements for Hazardous Material Reduction (e.g., the Red List) and Material disclosure (e.g., Declare Labels and the HPD v2). This standardization allows architects to find and choose the right products for their projects while also meeting the most stringent environmental products in the market today.
3. End-use application
There are countless end uses for coated metal building products from roof and wall panels, to aluminum extrusions for curtainwalls. Depending on the project and application can weigh into choosing a coating finish.
4. Achieving a certain aesthetic
Coil and extrusion coatings offer limitless design possibilities. What color is desired? Do you want to a bright vivid color? A metallic or wood look? Determining what the look and feel for your finished product is an important step of the process. Coatings can inspire you to create a memorable design with distinct angles. With color-changing pigments create a consistent iridescent, gradient look that makes building colors shift when viewed from different angles or lighting. Or include an intense sparkle element that can be combined with any color in architectural coatings.
Once you’ve considered the location, sustainability requirements, end-use and aesthetics, it’s critical to identify a partner who can help guide you from blueprint to grand opening. Partner with a coatings provider that has a solid reputation for quality, integrity and dependability.
Mark MacDonald is the sales/market manager at Sherwin-Williams Coil Coatings, Minneapolis. For more information, visit coil.sherwin.com.