The document discusses different types of roof trusses including king post truss, queen post truss, Howe truss, Pratt truss, fan truss, and north light roof truss. It describes the advantages of roof trusses such as being cost effective, allowing for quick installation, and providing stability. Tubular steel trusses are discussed as being used for large span constructions over 25-30 meters. The advantages of tubular steel trusses include reduced maintenance costs and corrosion resistance compared to other materials.