Types of metal tile coatings

Metal tiles are unique among roofing materials because of their strength, adaptability, and visual appeal. The kind of coating put on the metal surface is one of the main elements affecting their functionality and look. These coatings improve the tiles’ longevity and aesthetic appeal in addition to shielding them from the elements.

Metal tiles are frequently coated with a variety of coatings. Polyester coating is a widely preferred choice due to its cost-effectiveness and fundamental ability to withstand weather conditions. Because polyester-coated metal tiles come in an array of colors, they are an adaptable option for both commercial and residential roofs.

Silicone-modified polyester (SMP) coatings offer improved fading resistance and durability compared to ordinary polyester. SMP coatings are appropriate for regions with harsher weather conditions because they provide superior protection against UV rays and environmental wear.

Polyvinylidene fluoride (PVDF) coating is another high-end option; it’s frequently sold under brands like Hylar or Kynar. PVDF coatings offer exceptional durability, fading resistance, and color retention. They are perfect for roofs in areas with a lot of pollution or drastic weather changes.

Additionally, some metal tiles have acrylic coatings that provide a moderate level of color retention and durability. While acrylic coatings might not offer as much protection as SMP or PVDF coatings, they are valued for their low cost and ease of maintenance.

Galvanized Steel A durable and economical option, coated with zinc to resist corrosion.
Aluminum Lightweight and resistant to corrosion, ideal for coastal areas.

It all starts with galvanizing

Metal tile corrosion prevention is always a multifaceted process. Steel is galvanized first, then passivated for improved zinc fixation and extra protection, primed, and finally a polymer coating is applied. Even the least expensive kinds of metal tiles can last for at least ten to fifteen years before the first corrosion foci show up thanks to this protective "pie."

As a result, the qualities of the zinc layer have an impact on the roofing material’s longevity in addition to the metal tile’s type of coating. Furthermore, this influence is very strong: the service life varies by 1.5–2 times, even though two types of steel may have the same polymer protective layer. This results from varying galvanizing densities, or, to put it another way, from a zinc expense per meter squared of metal.

Four classes can be conditionally assigned to the metal tile based on the thickness of its zinc coating:

  1. First grade with galvanizing density 275 g/m 2 or more. This is a European standard for roofing materials.
  2. Second class With the density of the zinc layer 180-275 g/m 2 . Steel with this coating is also quite high quality.
  3. Third class with zinc coating density 142.5-180 g/m 2 . The metal -coating of this type shows itself well in gentle conditions, but in regions with a complex climate begins to rust much faster than the material of the first class.
  4. Fourth grade with galvanizing density 100-142.5 g/m 2 . Very low -quality, but cheap material that can only be used in temporary buildings with a limited service life.

Even European businesses manufacture metal tiles with coatings that have a maximum density of 350 g/m 2. This material is rare and not used in private construction in Russia because it is costly and meant for extremely difficult conditions.

Ceterisis equal, zinc coatings with a consumption of less than 142.5 g/m 2 will obviously not last as long as metal tiles with a density of 275 g/m 2. However, this type of metal tile also costs a lot more. In this sense, second- and third-class materials are a compromise, and private homes typically select them.

Polymer coatings of metal tiles

Numerous types of polymer protective coatings for metal tiles. However, based on the polymer at the center of the mixture, each of them falls into one of four categories:

  • inexpensive polyester coatings;
  • premium polyurethane coatings;
  • Popular plastisol (PVC) especially resistant to mechanical damage;
  • Chemically persistent coating from PVDF.

In the meantime, any kind of coating can benefit from the addition of different polymers and additives to enhance its fundamental characteristics.

Polyester: Bright and affordable standard

Lustrous polyester It is coated with a 25 μm layer of polyester on metal. This kind of polymer coating for metal tiles is the least expensive, but it has other benefits as well. Elastic polyester coating effectively prevents corrosion on the metal, can tolerate significant temperature fluctuations, and is highly resistant to chemical influences. Its color diversity is also the greatest; most manufacturers include 30 to 40 shades in their palette, which is far more than that of any other polymer coating type.

But the polyester coating on the metal tile will not keep its color for the full service life; after ten years, it will start to fade dramatically in the sun. Furthermore, the polyester protective layer is brittle in terms of mechanical damage since it tears and scratches easily.

As a result, a metal tile coated in glossy polyester has a comparatively short lifespan. The metal tile has a 20-year lifespan if the material’s foundation is made of steel and has first-class galley. In areas with mild weather, for a maximum of 25 years.

The polyester coating has a matte finish in addition to gloss. In this instance, a 35 micron layer of polyester has been applied, and because of additions, its surface is rough. Although the color of a matte polyester coating is less varied, it is more resistant to ultraviolet light and effectively prevents metal from corroding; a tile made of metal with this kind of coating will last 25 to 30 years.

Polyuretan: when the roof is for a long time

Metal coated with polyurethane is an expensive material. A strong polyurethane protective layer is incredibly resilient to mechanical stresses; it is nearly impervious to abrasion during transit and is nearly unscathed when snowfall falls from the roof. High resistance to alkalis, acids, and salt solutions enables you to construct metal-coated roof polyurethane for houses situated close to global reservoirs, industrial facilities, and loaded vehicles. Furthermore, polyurethane coating is resistant to temperature extremes and effectively maintains color.

Polyamide and acrylic are two common polymers used to modify polyurethane. The polyurethane coating can be textured, smooth and matte, or extremely durable, depending on the additives.

A metal-covered tile has a 40–50 year service life.

Plazor: Ultra -resistant exotic

Plazole is an uncommon PVC coating for metal tiles that has plasticizers added to it. The playsol coating is applied in a very thick layer (roughly 200 microns), which greatly increases its resistance to mechanical damage. PVC is resilient to acids and alkalis, just like polyurethane. The metal tile’s playsol coating, which occasionally has an embossed pattern, provides relief without glare.

A metal tile with a plasticizol protective layer typically lasts 25 to 30 years despite its substantial thickness. Extreme temperature changes and particularly intense heating are not tolerated by this coating. It does not suit the southern regions, for this reason. Furthermore, the plasticizer burns out in the sun very quickly.

PVDF: Colorful and reliable

Acrylic polyvinyl fluoride makes up PVDF coating. It is advised to use the material with such a protective layer on coasts, in industrial zones, and other locations with unfavorable conditions because it is the most chemically stable type of coating for metal tiles.

PVDF coating auto-cleans and flawlessly holds color. Exclusive shades of metallics are included in the palette, along with special pigments that are especially persistent added to the polymer composition.

One drawback of PVDF 2. Because of its slightly higher thickness than polyester (27–28 microns), the PVDF coating’s strength is not as high as polyurethane’s. Furthermore, the cost of applying such a metal tile coating is high.

30 to 40 years of service for the safe PVDF metal tiles.

With a variety of coating options to meet varying needs and tastes, metal tiles are a flexible roofing material. Every kind of coating has benefits of its own, ranging from increased durability to improved appearance.

Because they are rust-resistant and fit for a variety of climates, galvanized metal tiles are widely used. They are reasonably priced and offer consistent corrosion protection over time.

Polyester coated metal tiles are a more aesthetically pleasing choice because they come in a variety of colors that go well with any type of architecture. Both residential and commercial buildings gain aesthetic value from these coatings because they are long-lasting and retain their vibrant appearance.

Metal tiles with a PVDF coating are well known for their remarkable stain and fade resistance. They provide enduring protection while maintaining the integrity of their color, making them perfect for locations with severe weather.

In conclusion, a variety of factors, including climate, desired aesthetics, and budget, influence the choice of metal tile coating. In order to guarantee a long-lasting and aesthetically pleasing roofing solution, homeowners and builders can make more informed decisions by being aware of the advantages of each type.

Metal tile coatings provide a variety of choices that improve the performance, look, and longevity of roofing materials. Every kind of coating has a distinct function, from rust-prevention protective coatings like zinc and aluminum to decorative finishes like colored polymers and stone granules that enhance curb appeal. Making educated decisions about which of these coatings to use can help builders and homeowners ensure that their roofs will not only look great but also withstand the elements for many years to come.

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Denis Shcherbakov

Professional roofer with 20 years of experience. I know everything about the installation, repair and maintenance of various types of roofs. I will be happy to share my knowledge and experience with you.

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