19 Articles of concrete for construction purposes; building panels, not of metal; building requisites of non-metallic materials, namely, pre-cast concrete wall forms, bricks, composite panels composed primarily of nonmetal materials, mortar for building; cementitious building materials other than in the nature of paint; concrete articles for building walls, namely, concrete panels, concrete walls; concrete blocks; concrete building elements, namely, blocks, bricks, posts, slabs, and panels; concrete prefabrications, namely, pre-cast concrete wall forms; concrete products for use in building, namely, ready to use concrete; constructional members of aerated concrete for use in building, namely, aerated concrete blocks; manufactured bricks; non-metallic building blocks of concrete; non-metallic building bricks; non-metallic building elements, namely, concrete slabs and manufactured brick veneer for use on interior and exterior walls; non-metallic materials for use in the construction of walls, namely, wall panels not of metal; non-metallic prefabricated building elements, namely, pre-cast concrete wall forms; non-metallic prefabricated building elements for onsite assembly, namely, pre-cast concrete wall forms; concrete masonry blocks; bituminous products for building, namely, concrete; non-metallic prefabricated wall structures in the nature of wall panels; non-metallic prefabricated walling in the nature of wall panels; non-metallic concrete walls; non-metallic concrete walls for buildings; preformed concrete building elements in the nature of ready to use concrete; non-metallic ready-made building components, namely, transportable buildings and wall systems consisting of reinforced, dry-stacked, engineered concrete block with insulating core and coated with surface bond cement; rendering compositions for use in building, namely, asphalt paving compositions; walling of non-metallic materials, namely, concrete walls for building; blocks made of non-metallic materials for building purposes, namely, concrete blocks, paving blocks and refractory blocks; cladding, not of metal, for building; non-metallic cladding for walls for building; non-metallic cladding panels for building walls; non-metallic building materials for the covering of walls, namely, slates for wall cladding; non-metallic weatherboards; plaster boards; non-metallic linings for walls in the nature of wall panels not of metal; studding being non-metallic framing for building walls; wall ties, not of metal; stone veneers; bonding mortar for building purposes; bricks; building elements made of non-metallic materials, namely, mortar for building; building materials having bonding properties in the nature of cement bonded particle boards