1 Best fireproof and waterproof 2. Light weight, heat insulation 3. Installation is easy Rockwool wall sandwich panel:Steel Thickness ... steel of panelsLifetime: 15~20 yearsCharacter: Light in weight, heat insulation, fireproof and waterproof, benvironmental Usage: various roofs and walls ... large size factory buildings, storages, exhibition halls, gymnasiums ,etc Insulation rock wool sandwich panel