Z / C Section structural members designed for use as secondary supports for roof sheeting and where applicable insulation and liner trays for spans up to 10.0 m depending on the load to be applied and where the cladding or liner tray offers adequate support by virtue of its fixings i.e., fixed according to sheet manufacturer’s instructions. Z / C Sections are manufactured from ASTM A653 structural quality pre-hot dipped galvanized sheet to G90 with minimum guaranteed yield strength of 345 N/mm2.