A part of the galvanized steel production is corrugated to produce galvanized corrugated steel sheets (GC sheets). Corrugated galvanized steel sheets are at present the best known, most widely available low cost roof covering material. These sheets are lightweight roofing material made of thin sheets, stiffened by corrugations. Corrugations, such as waves, considerably increase the strength and stiffness of the light-weight material. There is a large variety of qualities of corrugated steel sheets which are available in the market. These sheets are very popular. Most of the corrugated sheets are light-weight and considerably of low cost.
Corrugated galvanized steel sheets are made of thin plain galvanized steel sheets, stiffened by corrugations. The corrugations, such as waves or folds, increase the strength and stiffness of the sheeting material considerably. Without these waves, the sheets have limited load bearing capacity and are highly deformable. The sheets are normally made of mild steel, which is then galvanized to increase the resistance against corrosion and increase the durability or service life.
The quality and performance of corrugated galvanized steel sheets is determined by three main criteria namely (i) for stability and resistance to loads which are its dimensions, especially its thickness and the type of corrugation, (ii) for durability (resistance to corrosion) service life and appearance which are due to the type of galvanizing or coating used, and (iii) for durability (resistance to corrosion) and service life which depend on the thickness of the galvanization / coating on the sheet surface. The weight per surface area has less direct relevance for the performance of the sheet.
The basic measurements of corrugated galvanized steel sheets are (i) corrugation pitch, (ii) corrugation depth, (iii) ray of arch, (iv) number of corrugation pitch, and (v) number of crests (corrugations).
