37 Construction and installation of prefabricated walling, wall panels, building panels, panel boards, building blocks, building partitions, walling systems and lintels; erection of curtain walling; repair and maintenance of prefabricated walling, wall panels, building blocks, building panels, panel boards, building partitions, panel mouldings, loading and non-loading panels, walling systems, lintels, roofs, floors and ceilings