19 Building materials, not of metal, namely, synthetic boards for building purposes, [ ceiling boards, not of metal, ] [ stone for building and construction, ] window glass for buildings, window frames, not of metal, windows, not of metal, panels, not of metal for building, casement windows, not of metal, doors, not of metal, door frames, not of metal, door panels, not of metal [, fences, not of metal, gates, not of metal, roof coverings, not of metal, balustrades, not of metal, artificial marble, plaster, plywood, wall claddings, not of metal, for building, floor boards, not of metal, wall boards, not of metal, building timber, moldable wood in the nature of wood moldings, partitions, namely, wall boards, not of metal, insect screens, not of metal, shutters, not of metal, tiles, not of metal, for building, joinery fittings, not of metal, prefabricated building assembly kits, not of metal, cement ]