19 NON-METALLIC BUILDINGS, NON-METALLIC BUILDING MATERIALS AND PARTS-NAMELY, TIMBER, PLASTERBOARD, CHIPBOARD, PLYWOOD, SLATE, CONCRETE, WEATHERBOARD MADE OF THE AFOREMENTIONED MATERIALS, PARTITIONS MADE OF THE AFOREMENTIONED MATERIALS, WALL TILES, INTERIOR WALLS, EXTERIOR WALLS, EXTERIOR WALL FACINGS AND INTERIOR WALL FACINGS, TIMBER FRAMES, CONCRETE PANELS, FLOORS, AND JOISTS