Cold-rolled steel is used as basic material for manufacture of metal roofing tiles, profiled metal sheets, section plating etc. After rolling the steel sheet undergoes hot galvanization, thus making its surface resistant to corrosion. Galvanization also prepares the surface for application of the next layer by passivation process. After that the surface is covered by primer and a layer of colour plastic able to resist sun rays and temperature fluctuations influence. Polyester is considered to be the most suitable material to be used as cover in our climatic condition. This material is twice as resistant to high temperature as plastisol, which is very significant for construction in southern latitudes. Is also has no microcracks which are source of corrosion.
Plain sheets are also used as raw material for manufacture of roofing elements (roofing planks), drain systems, air ducts etc. Length 1÷10 m, width 1250 mm, thickness 0,35÷0,7 mm. Coating: Zn, zinc-aluminium alloy and gloss polyester with thickness of micrometers. Colour according to RAL matching system.