Building materials, namely, plastic pipe supports; Insect screens, not of metal; Non-metal air conditioning ducts; Non-metal chimney cowls; Non-metal construction materials, namely, Ventilation ducts and connections; Non-metal roof vents for ventilation in residential and commercial buildings; Non-metal vent cover for HVAC ducts; Non-metal vent covers for roof deck protrusions, drains and pitch pans; Non-metal ventilating ducts; Polyethylene pipe used in geothermal heating and cooling systems...