... thermal conductivity<=0.023 w Polyurethane (PU)sandwich panel MODEL 950/1000advantage:warm keepingcertificate: ISOthermal conductivity<=0 ... AS FOLLOWS:1). ROOF MODEL 950/1000model2).panel Thickness: 50 TO 75mm steel plate thickness ... time, easy installation.8). Installation: one sandwich panel sheet one side overlap the other one, then ... the sides, roof ridges, cross-joint, on interior gutters, etc.