What are the recommended thickness and type of a filling material for wall and roof sandwich panels?Wall and roof ready-to-use sandwich panel thickness basically depends on Construction Norms and Rules requirements or Building codes (wind and snow climatic zones, loads on columns, beams, roof, etc.) and functional purpose of a steel building. WebSteel system during project designing automatically takes into consideration climatic zones as well as Russian and foreign Construction Norms and Rules requirements (building codes) Usually, clients prefer mineral rock wool as the filling material because of its incombustibility with the thickness of 100 mm for walls and 120 mm for roof. Sometimes, international clients can ask for polyurethane foam as the most effective type of a filling material. Although its cost is higher it has advanced thermoinsulation properties.