... steel or Z section SteelHeat insulation material 1)External wall panel : (below is selectable )* 50mm,75mm,100mm thickness EPS ... corrugated galvanized steel sheet with different color 2)Internal wall panel : (below is selectable )* 50mm,75mm,100mm thickness EPS ... sandwich panel '* 50mm,75mm,100mm thickness Rock sandwich panel '3)Roof panel (below is selectable )* 50mm, ...