Corrugated galvanised iron (CGI) sheets are very popular in all parts of the country, except in the high mountains. These sheets shall be properly anchored to each purling/batten that supports them. Corrugated Galvanized Iron or Steel sheets are a lightweight roofing material made of thin sheets, stiffened by corrugations. Corrugations, such as metal sheets are fragile and highly deformable. The steel used is mild steel for forming, which is galvanized to increase the durability of the metal sheets and consequently allowing them to better withstand the weather.