Metal Roofing Paint Systems: SMP vs PVDF Coatings

SMP vs PVDF Coatings

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Jun 19, 2022

Metal Roofing Paint Systems: SMP vs PVDF Coatings

Once you choose a metal roof for your home or business, there are a number of choices that need to be made; the type of metal, whether you’ll have a snap lock or mechanically seamed profile, the paint system, and the color of the roof. At Gravity Metal Roofing, we customize each metal roof installation to our client’s individual needs and most of the choices that go into a metal roof are based on what will provide the most protection for the building and result in the most durable and long lasting metal roofing system.

A metal roofing system’s success depends on its waterproofing ability. Rust and corrosion not only detract from the metal roof’s appearance, but also reduces the service life of the metal roof by compromising its waterproofing ability. Technology has greatly advanced materials in the roofing industry. Paint and coating systems used for metal roofing panels greatly extend the functional life and beautiful appearance of a metal roofing system. Two of the most popular paint coating systems for metal panels are SMP and PVDF. Keep reading to learn more about which paint system may work best for your metal roofing project.

Metal Roof Coatings

When you choose a color for your metal roof, the metal panels are painted or coated. Due to technological advances, modern finishes offer more than just aesthetic value. They not only make your metal roof look beautiful, but they also protect the metal roofing panels from the elements, UV exposure, chemicals in the atmosphere, moisture, and pollution.

When you invest in a metal roof, you are choosing a roofing system that can endure the test of time. Metal panel finishes must withstand peeling, cracking, and discoloration while providing superior fade resistance and chalking. This is especially important in regions that experience high heat and UV exposure, such as central and south Texas.

In this article we will discuss SMP and PVDF paint systems for your metal roof. The difference in chemical structure between the two paint systems mean that they perform differently. Being aware of these differences will allow you to make an informed decision when investing in your home or business.

What Causes Fading and Chalking

Constant UV radiation, pollution, chemicals in the atmosphere, and moisture results in the chemical breakdown of a coating’s base resins and pigments which results in fading and chalking. Fading is the visible loss of color over time. Chalking refers to the formation of a powdery substance on the surface coating of metal roofing panels. Both fading and chalking result from exposure to the elements. How long fading and chalking take to occur varies, but there are certain climates that will speed up the process.

For example, a black metal roof in the Northeast will likely fade slower than a black metal roof in Texas. Also, the areas of a roof that receive less UV rays will fade visibly slower than areas that experience constant direct sunlight. Metal roofs are great for coastal properties, but the salt in the atmosphere can accelerate the fading process. Areas that experience extreme temperatures can cause the chemical makeup of the paint to be weakened with frequent temperature fluctuations. A metal roof is a great option for all these conditions if the right care is taken in choosing the roof’s installation method, profile, and color which can all offset the effects of the environment on the roof, resulting in a long lasting and durable roofing system.

When it comes to chalking, environmental factors contribute less to the appearance of the white residue, although climate does play a role in how quickly chalking happens. Exposure to UV rays is probably the most important factor to consider if you are concerned with chalking. Chalking will also be less apparent on a lighter colored, or gray colored metal roof because the chalky residue blends with the color of the roof. Although a lighter colored roof will not stop chalking from eventually occurring, it will be less noticeable.

Metal roof paint systems combat the harmful effects of the sun’s UV rays and can extend the life of your metal roof. Fading and chalking can keep a metal roof from looking fresh and new. Although fading does not affect a metal roof’s performance, it will impact a metal roof’s appearance. Fading is always less noticeable with neutral colors such as white, tan, or light stone. Both fading and chalking will take much longer to happen with a PVDF paint system than an SMP paint system. Keep reading to learn why the chemical makeup of these paint coatings greatly affect their performance and the appearance of your metal roof.

What is an SMP Paint System?

SMP Coating is a popular, middle level quality, silicone-modified polyester resin. SMP coatings are made by blending polyester with silicone intermediates and ceramic pigments, resulting in a beautiful color, outstanding gloss retention, and increased weather resistance. Generally, resins with a higher silicone content have a corresponding level of performance. This is because silicone improves gloss retention and weather resistance. However, technological advances in ceramic pigments allow for lower levels of silicone to be used without sacrificing color and gloss retention or performance. The amount of silicone used in SMP coatings can vary depending on the manufacturer.

Reputable paint manufacturers only use ceramic and select inorganic pigments in their SMP paint formulations. SMP paint systems using high quality pigments and silicone can potentially approach the durability and efficiency of premium PVDF coatings, but it is important to note that PVDF will still outperform SMP in terms of color and gloss retention.

It is the silicone in the SMP paint that helps protect the metal roof’s color from fading. This is why SMP outperforms less expensive polyester paints that do not have silicone in them. However, it’s important to note that fading will happen eventually, resulting in a lighter, dull, or uneven color.

SMP coatings also possess energy efficient properties due to their solar reflectance. Typically, the lighter the metal panel’s color, the more efficient the panel is. This is because lighter panels have a higher ability to reflect a portion of solar radiation away from the metal roof’s surface, potentially reducing energy costs. Darker colors tend to absorb energy, resulting in heat transference to the building’s interior.

SMP, like all paint systems, is permeable and should only be used with a quality metal substrate. Keep in mind that there is quite a lot of variation in quality within the SMP paint category depending on the makeup of the resin. This is where hiring a roofing company that specializes in metal roofing can make the difference in the quality of your metal roofing installation. At Gravity Metal Roofing, we understand our materials and how they all interact to provide the best roofing system possible for your budget. Investing in a high quality resin for a poor quality substrate is a formula for premature material failure.

Best Use for SMP Paint Systems

SMP paint systems are primarily used on light gauge metal panels, with a gauge thickness of 26 or 29. In addition, SMP panels are often used for metal siding. This is because metal siding experiences less direct UV exposure as metal roofing.

While there are many colors to choose from in SMP coatings, certain colors within the SMP paint category experience better color and gloss retention than others. The colors that work best with SMP paint systems tend to be earth tones and shades of white because fading is less noticeable.

What is a PVDF Paint System?

The chemical structure of PVDF coatings give them their durability and longevity. PVDF, or polyvinylidene fluoride coatings, consist of on of the strongest known chemical bonds, the carbon-fluorine bond.

PVDF is a high performance paint system with superior resistance to premature fading and chalking. For this reason, it is generally the preferred paint system for metal roofs. The painted surface of metal roofing systems suffers high exposure to the damaging effects of UV rays and debris so having a paint system that is resistant to abrasion, fading, and chalking is critical for the lifespan of your roof. A superior paint system will allow your metal roof panels to maintain their aesthetic quality longer than lower priced paint systems.

PVDFs chemical makeup gives it the extraordinary ability to retain its vibrant color longer than other metal roofing paint systems. All metal roof paint systems will fade over time, but PVDF offers extraordinary resistance to color/gloss loss and chalking. A metal roof that has not been treated with an adequate fade resistant paint system will fade unevenly in areas that receive shade vs areas that receive constant sun exposure. The part of the roof that experiences the most UV exposure will look duller than the shaded area. Chalking is inevitable on a metal roof, but the strong chemical bonds of PVDF paint systems make it more resistant to the effects of the sun and delays chalking when compared to lower quality paint systems. For these reasons, PVDF will be a higher priced paint system, but it will extend the longevity of your metal roof’s appearance.

PVDF paint systems also offer energy efficiency. Metal roofs are inherently energy efficient due to their solar reflectivity. A high quality PVDF coating has the potential to enhance the roof’s energy efficiency and potentially reduce cooling costs, an important consideration in central and south Texas.

As we mentioned earlier in the article, it is important to pair materials that are like in quality. If you invest in a high quality metal panel for your roof, you want to use a high quality paint system to protect it as a lower quality paint system may cause your roof to degrade faster. If you are making a significant investment in your roof, a PVDF paint system will be the right choice. PVDF paint systems are available in a wide variety of custom colors and finishes including vibrant colors, rusted colors, wood colors, zinc colors, copper colors, and matte finishes.

Comparing SMP to PVDF Paint Systems

PVDF paint systems have an exceptionally long lifespan. While every manufacturer warranties their PVDF paint systems differently, they usually always cover fading and chalking for more years than SMP paint systems. SMP paint systems have limited color options, but PVDF panels are available in a wide variety of custom colors and finishes.

SMP paint systems offer higher resistance to abrasion and scratching. It is important to note that the hardness of SMP paint can make the metal panel less flexible and it may be more susceptible small fractures in the coating. PVDF paint is soft, making it easier to scratch so extra care needs to be taken during transportation and installation. Panels are covered with a peel off protective plastic during transport that is removed after the installation. Because PVDF is softer, it is also more flexible, meaning that it is less likely to crack or fracture on flexible metal panels.

PVDF coatings are typically regarded as the superior paint system in terms of quality and performance, however they do cost more than SMP panels. It is important to decide what your priorities are for your metal roof. If you are looking for a vibrant color or specific finish, it is most likely that PVDF will be the paint system of your choice.

Metal Roofing Companies Near Me

Hiring a local roofing company that specializes in metal roofing is important. A metal roofing company will have exceptional product knowledge and experience. As you can see there are many factors that affect the lifespan of your metal roof, and you want to be sure the company that you hire has the experience to understand how each component of your roof will work together.

At Gravity Metal Roofing, we are focused solely on metal roofing. We understand how the different components of metal roofing systems interact and how they affect the overall performance of your metal roof. We understand that a metal roof is an investment in your home, and you want a product that will last as long as possible and will look good many years after the initial installation. Gravity Metal Roofing customizes every metal roof installation for the building it is designed to protect, giving every project and every client the attention that they deserve. Call us today at (844) 352-7663 for your metal roofing consultation.

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