19 Non-metallic building materials, namely, pipe supports, cable tray supports and ductwork supports for heating, ventilation and air-conditioning systems and installations, rigid pipes and tubes, valves and fittings, junctions and supports, hangers and support structures for pipe and ductwork all for use in heating, refrigeration, ventilating and air-conditioning installations, and pipe supports, cable tray supports and ductwork supports for mounting solar panels; non-metallic rigid pipes and rigid tubes, and fittings and valves therefor sold as a unit with the aforementioned pipes and tubes; non-metallic rigid pipes for building; non-metallic ducting [not for electrical circuitry]; non-metallic clips, brackets and clamps for fixing guttering, pipes and supports to buildings; non-metallic junctions for air dispersion ducts; non-metallic frameworks for use in buildings; non-metallic protective guard railings; non-metallic stairs and steps; non-mechanical and non-metallic walkways; non-metallic hangers for pipes; apparatus for the support of pipes, namely, plastic pipe supports; non-metallic supports for ductwork; non-metallic adjustable supports for ductwork; non-metallic fittings in the nature of brackets and supports for fixing refrigeration, air-conditioning, ventilating and heating installations on and to buildings; non-metallic grilles being non-metal gratings for use in heating, refrigeration, ventilating and air-conditioning installations; non-metallic supports for HVAC-R plant, equipment and installations; asphalt, pitch and bitumen; non-metallic transportable buildings; non-metallic frameworks for use in rooftop equipment support systems, non-metallic frameworks for use in HVAC-R support systems comprised of frameworks and frames, stands and supports, non-metallic clips, non-metallic clamps, non-metallic supports, and non-metallic hangers; non-metallic modular frameworks for use in rooftop equipment support systems, non-metallic modular frameworks for use in HVAC-R support systems; non-metallic modular supports for rooftop equipment, non-metallic modular supports for HVAC-R systems, apparatus and equipment comprised of frameworks and frames, stands and supports, non-metallic clips, non-metallic clamps, non-metallic supports, and non-metallic hangers; non-metallic components for modular non-metal supports for rooftop equipment, non-metallic components for non-metal supports for use in the support of HVAC-R systems comprised of frameworks and frames, stands and supports, non-metallic clips, non-metallic clamps, non-metallic supports, and non-metallic hangers; fitted parts and fittings for the aforementioned goods sold as a unit with the aforementioned goods