Gypsum for use as building materials; prefabricated houses, not of metal; works of stonemasonry in the nature of building stone ; works of art of stone, concrete or marble; building stone;building materials, not of metal, namely, plastic building materials in the nature of plastic pipe supports and plastic boards; stone mosaics for building; wall claddings, not of metal, for building; wood panelling; building panels, not of metal; parquet flooring; tiles, not of metal, for building; slabs, no...