If you want to buy a metallic roof system you have to know that for a solid roof, three conditions must be met: a high quality raw material, profiling on high-performance automated lines and qualified assemblage. Regarding the raw material, the most important characteristics are the type of steel, the thickness of the sheet, the zinc coating and the paint coating. All this aspects influence the guarantee and the life span of the product.
There are two types of steel used for producing metallic sheet tiles: S250GD and DX51D. The main difference between the two of them is bound to their plasticity, the first one being recommended to produce metallic tiles. Wetterbest® uses this steel – S250GD.
The raw material for Wetterbest® is galvanized sheet steel or pre-painted aluzinc, with a thickness of 0.5-0.55 mm, purchased from leading pre-painted steel manufacturers in Europe.
The zinc coating is designed to protect against corrosion and bad weather. The thicker the coat of zinc is the harder is for the oxygen from the atmosphere to reach the base material, the iron, which is the main component of steel. This is important considering that iron, over time, under the action of oxygen, starts to corrode. Also, a thick coating of zinc prevents paint to get into the base material, which could lead to peeling of the paint. Therefore, the zinc coating should be neither too thick, nor too thin.
The zinc coating of the raw material used by Wetterbest® has a thickness between 225 and 275 g/mp.
For metallic sheet tiles, Wetterbest® uses steel coated with a paint based on:
• Shiny polyester – 25 μm
• Matte polyester – 35 μm
• Matte polyurethan – 50 μm
For the drainage system the paint can be based on:
• polyester /polyurethane – 35 μm
• PURAL – 35 μm
The quality of the raw material is reflected in the pre-painted sheet steel manufacturer’s warranty. The better the quality of the material, the higher the warranty. In the case of the Wetterbest® metallic sheet tiles, for a thickness of 0.5mm, a zinc coating of 225-275 g/m² and a paint coating of 25-35 microns, the manufacturer’s warranty is of 15 years and for a paint coating of 50 microns, the manufacturer’s warranty is of 35 years.