Galvanised Corrugated Sheets:

Galvanised Corrugated steel or iron 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.

GCS is lightweight and easily transported. It was and still is widely used especially in rural and military buildings such as sheds and water tanks.

The corrugations are described in terms of pitch (the distance between two crests) and depth (the height from the top of a crest to the bottom of a trough). It is important for the pitch and depth to be quite uniform, in order for the sheets to be easily stackable for transport, and to overlap neatly when joining two sheets. Pitches have ranged from 25 mm (1 inch) to 125 mm (5 inches). It was once common for GCS used for vertical walls to have a shorter pitch and depth than roofing GCS. This shorter pitched material was sometimes called "rippled" instead of "corrugated". However nowadays, nearly all GCS produced has the same pitch of 3 inches (76 mm).