Corrugated Galvanised Iron (colloquially corrugated iron or pailing (in Caribbean English), commonly abbreviated CGI) is a building material composed of sheets of hot-dip galvanised mild steel, cold-rolled to produce a linear corrugated pattern in them. The corrugations increase the bending strength of the sheet in the direction perpendicular to the corrugations, but not parallel to them. Normally each sheet is manufactured longer in its strong direction.
CGI is lightweight and easily transported. It was and still is widely used especially in rural and military buildings such as sheds and water tanks. Its unique properties were used in the development of countries like Australia from the 1840s, and it is still helping developing countries today.
Today the corrugation process is carried out using the process of "Roll Forming". This modern process is highly automated to achieve high productivity and low costs associated with labour. In the corrugation process sheet metal is pulled off huge rolls and through rolling dies that form the corrugation. After the steel sheet metal passes through the rollers it is automatically sheared off at a desired length. The standard shape of corrugated material is the round wavy style, but can be easily modified to a variety of shapes and sizes by simply changing the dies.

Corrugated Galvanised Iron (colloquially corrugated iron or pailing (in Caribbean English), commonly abbreviated CGI) is a building material composed of sheets of hot-dip galvanised mild steel, cold-rolled to produce a linear corrugated pattern in them. The corrugations increase the bending strength of the sheet in the direction perpendicular to the corrugations, but not parallel to them. Normally each sheet is manufactured longer in its strong direction.
CGI is lightweight and easily transported. It was and still is widely used especially in rural and military buildings such as sheds and water tanks. Its unique properties were used in the development of countries like Australia from the 1840s, and it is still helping developing countries today.
Today the corrugation process is carried out using the process of "Roll Forming". This modern process is highly automated to achieve high productivity and low costs associated with labour. In the corrugation process sheet metal is pulled off huge rolls and through rolling dies that form the corrugation. After the steel sheet metal passes through the rollers it is automatically sheared off at a desired length. The standard shape of corrugated material is the round wavy style, but can be easily modified to a variety of shapes and sizes by simply changing the dies.