19 Non-metallic building materials, namely plaster, shingles, tiles, wood panels, glass fibre insulation, cladding for construction and building, lumber; drain, gutter, plumbing and sewer pipes; non-metallic manhole covers, and manhole frames, non-metallic drainage gratings, non-metallic inspection covers, namely manhole covers and duct covers providing below ground access to drainage and sewer systems, well covers, and duct covers; non-metallic drainage and sewer systems, apparatus and installations made therefrom, namely sewer pipes, drain, gutter, plumbing and sewer valves, sewer rods, sewer fittings, pipe work couplings; non metallic building and construction articles, namely bricks and concrete, glass, paving, and wood blocks