raw or semi-worked rubber, gutta-percha, raw or semi-worked gum, asbestos, mica; plastics in extruded form for use in manufacture; packing, stopping and insulating materials for lining, sealing or repairing a damaged pipe, made wholly or predominantly of plastics material, elastomeric material, nitrile rubber or polyvinyl chloride, and parts and fittings therefor; flexible pipes, not of metal; pipes, pipe couplings, pipe adapters including adaptor couplings for coupling pipes of different sizes, made wholly or predominantly of plastics material, elastomeric material, nitrile rubber or polyvinyl chloride, and parts and fittings therefor; bushes being non-metal fittings for pipes for use in the jointing of pipes; sealant compounds for joints; semi-finished products, namely, artificial resins; semi-finished products, namely, synthetic resins; air admittance valves, wholly or principally of plastic material, for soil, waste and ventilation pipes

drainage structures, namely, drain channels; drainage structures, namely, trench drains; drain end caps; drain mats; drain grates; drain bases; leaf guard covers for drain pipes; gutter covers; secondary moisture drainage apparatus, namely, troughs; secondary moisture drainage apparatus, namely, silt boxes; secondary moisture drainage apparatus, namely, collection boxes; drain pipe attachments;, namely, end outlets, corners and tees; all of the foregoing being non-metallic