Building materials, namely, plastic pipe supports, pre-cast concrete wall forms, non-metallic covers for ducts, tubes and polymeric duct assemblies, composite panels composed primarily of non-metal materials, railings, not of metal, non-metal bonding fasteners for mounting and demounting ducts, ducts containing cables, pipes, and ducts containing line sets; rigid pipes, not of metal for building; ducts and other casings for cables, not of metal; fittings not of metal, non-electric for ducts