Sheet metal roofing coatings - the basics of protection and aesthetic finish for years to come
When choosing sheet metal roofing, customers usually pay attention to aesthetics and price. These are understandable criteria that do not require specialized, technical knowledge. Meanwhile, there are a number of other very important issues that are worth taking a closer look at. One of the most important is the coating of the roofing material.
Sheet metal roofing is not a homogeneous panel, it has several different layers surrounding a steel core. The outermost layer is the paint coating. What is it responsible for? What are its properties? What to take into account to make the right choice? We explain this together with the Polish manufacturer of sheet metal roofing, Regamet.
Texture and color, i.e. the aesthetic function of a painted roofing coating
This is the most obvious property of the coating. As Regamet's expert says, aesthetics is the responsibility of its outer layer (varnish coating), under which the actual "heart of the product" covering the roof hides.
Whether the coating is perfectly smooth and glossy, or rather matte and heterogeneous (such a "coarse matte" texture characterizes the newest and best coating in our offer, PURTEXT STRONG 300), depends precisely on the type of coating chosen, explains Bartlomiej Ukowski.
The paint coating is also related to the color of the covering. It is worth knowing that, as a rule, manufacturers do not offer the same color range for all available coatings. Thus, the customer, when deciding on the choice of sheet metal roofing, considers three aspects in terms of aesthetics: shape, texture and color. Of those listed, only the first is unrelated to the coating chosen.
Protective functions of coatings
Protective coating - protection of roofing components during transportation and installation
Paint coating should also be considered in terms of thickness. In addition to aesthetic considerations, it also serves to protect against various damages that can happen during transportation and installation (such as any type of scratches or microcracks). The thicker it is, the better. The best coatings are characterized by a factor of 50 μm.
RUV - roofing protection factor against UV radiation and weathering
Roof coatings are exposed to unavoidable risks in the form of atmospheric factors, i.e. UV radiation.
The effect of solar radiation is one of the best tests of the quality of sheet roofing coatings," explains Bartlomiej Ukowski, Regamet's sales director. - Whether the roofing will still look aesthetically pleasing many years after installation depends precisely on the coating's resistance to UV radiation. In the case of sheet metal roofing, this is determined according to the 5-stage RUV coefficient. The higher the value of the coefficient, the greater the certainty that the roof will still make a good impression many years after installation, the expert adds.
Zinc corrosion protection layer of sheet metal roofing
Another danger that this type of roofing is exposed to is corrosion. Therefore, the layer of coating under the paint coating, and in direct contact with the steel core, is a layer of zinc, always given in grams (grams per square meter). In most cases, this parameter is Zn275 g/m², but as Bartlomiej Ukowski says, in the best coatings the zinc content is higher.
In the case of the PURTEXT STRONG 300 coating developed exclusively in cooperation with US Steel, the layer is as high as Zn300 g/m². Such a high zinc value provides roofing sheets or panels with increased corrosion resistance. Both after many years of contact with precipitation and as a result of cutting of individual elements during installation, corrosion outbreaks will be kept to a minimum, which is why, among other things, the aforementioned coating has been covered by us with as much as a 50-year warranty," explains Bartłomiej Ukowski.
It's good to know everything that a sheet metal roofing coating is responsible for. Having this knowledge, making a decision during the purchase will certainly be easier!
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