Painting and Protecting Metal Roofing: Anodized vs. Paint vs. Powder Coating
February 15, 2017 | By Mike Gonet | Filed under: Articles, Education, Green News, Metal Roofing, Technical
Any roof, no matter the style or color, is only a good one if it is durable and does not leak. Versatile and malleable, aluminum roofing is a wise, cost-effective option for your home. There are three good options for protecting metal roofing. Paint protects surfaces and adds color, but metal roofing is different from other materials. To protect the material from the elements and to visually enhance the result, metal roofing can be anodized, painted with liquid, or powder-coated.
Anodizing
Anodized aluminum roofing has a protective surface coating of aluminum oxide that is applied via an electrochemical process. Because it is durable and weather-resistant, anodizing is a common, effective, and long-lasting protection for applications like standing seam metal roofing. The thicker the anodic coating, the longer it lasts.
Anodized coatings may be dyed almost any color. They will also take on bronze overtones naturally due to a diffraction phenomenon the coating itself produces over time. Anodized metal does not lose its coating, which grows integrally from the base aluminum and thus neither peels nor flakes, permanently sealing the aluminum roofing underneath against the elements.
Painting
Painting or powder coating also protects and colors metal roofing. However, these paints and powders should be factory-applied rather than completed DIY. Of the many resin options, PVDF performs exceptionally well on metal roofing in harsh weather environments. PVDF-coated aluminum roofing generally outperforms anodized metal. It is not only resistant to extreme weather, but also to chemicals, UV light, flaking, and chalking. Also contributing to PVDF’s popularity is the nearly limitless range of color possibilities.
Kynar500® and Hylar5000® are the two leading products, virtually identical in all but name. Both yield the same superior-quality finishes; what is more, these products are usually warrantied for 30 years up to five Delta E units, which is the measure of the smallest perceptible color shift.
Powder Coating
Powder coating, on the other hand, is essentially “paint without the solvent.” Powder paints encapsulate pigment inside powdered resins. When composed of the same resins, the powder and liquid versions perform similarly by comparison. Because they are applied electrostatically after the product has been made, these “post-forming” double coatings not only beautify, but they also help correct any potential flaws or fissures in the base protective coating applied by the manufacturer.
A significant environmental benefit accrues due to less air pollution from the oven-curing manufacture process for powder coatings as compared to liquids. Kynar powder coatings are leaders in this innovative product category. When reflective metallic pigments are integrated into Kynar powder coatings, the stunning results are also money-saving. Reflective powder coatings deflect significant UV radiation away from the attic, keeping the house cooler and in turn reducing energy costs. When combined, Kynar paints and powder finishes provide superior color quality and long-lasting protection.
