Materials, not of metal, for building and construction; rigid pipes, not of metal, for building; lining for rigid pipes, not of metal, for building use; plastic conduits for drainage; drain pipes, not of metal; street gutters, not of metal; non-metallic drainage installations; rigid underdrainage pipes, not of metal; drain traps being valves, not of metal or plastic; drains, other than of metal or plastic; non-metallic waterproofing boards; non-metallic flashings for waterproofing buildings; ...