136 mm thick partition composed by 1 x 18 mm thick PregyPlac BA18 on each side, fixed to galvanized steel frame made of 40-100-40 mm horizontal U tracks and 47-99-50 mm vertical C studs. Mineral wool 80 mm thick in the cavity. According to fire classification report, glass wool with density less than 15 kg/m³ is permitted as insulation.