Non-metallic building materials; non-metallic pipes and tubes, and fittings and valves therefor; non-metallic rigid pipes for building; non-metallic ducting (non-electric); non-metallic clips, brackets and clamps for fixing guttering, pipes and supports to buildings; non-metallic junctions; frameworks for use in buildings (non-metallic); non-metallic railings; non-metallic protective railings; non-metallic stairs and steps; non-metallic walkways; non-metallic hangers for pipes; apparatus for the support of pipes; non-metallic support systems for ductwork; non-metallic adjustable support systems for ductwork; non-metallic fittings for fixing refrigeration, air-conditioning, ventilating and heating installations on and to buildings; non-metallic grilles; non-metallic goods for use in rooftop support systems; non-metallic frameworks for use in rooftop equipment support systems, non-metallic frameworks for use in HVAC-R support systems; 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 systems for rooftop equipment support systems, non-metallic modular systems for use in the support of HVAC-R systems, apparatus and equipment; non-metallic components for modular systems for use in rooftop equipment support systems, non-metallic components for modular systems for use in the support of HVAC-R systems; parts and fittings for the aforementioned goods