Building materials, none being composed wholly or principally of metal; partly built and wholly built foundation structures made therefrom; weight supporting elements for building and engineering constructions; concrete building elements including pre-cast concrete elements for use as foundation footings; paving blocks and slabs; bricks; angle brackets; pre-cast concrete, masonry and timber pilings and posts; concrete; cement; timber; non-metallic rigid pipes for use in connection with building; non-metallic transportable buildings