Abstract: To provide a process of treating particulates such as an inorganic powder or resin beads to impart water repellency, to effectively impart water repellency particularly to a porous inorganic powder or the like, without use of an organic solvent as a dispersion medium of a silicone oil. Water repellent particulates are produced by a first step of adding, to particulates, an aqueous emulsion of a silicon compound such as a silicone oil to apply surface treatment to the particulates with mixing and stirring in a dry state, and a second step of heating the treated particulates to bake the silicon compound on the surface of the particulates and to separate the aqueous medium in the emulsion. The aqueous emulsion of the silicon compound is preferably an aqueous emulsion of any one of methyl hydrogen silicone oil, dimethyl silicone oil, epoxy-modified silicone oil, amino-modified silicone oil, polyether-modified silicone oil and carboxyl-modified silicone oil.

Abstract: A flooring material for building comprises a wood overlaid board having a pair of side faces parallel to each other and a flexible sheet which is integrally layered on the back face of the wood overlaid board. The lower portion of the wood overlaid board is provided with a plurality of nick grooves which extend from one side face to the other side face. The nick grooves are formed to such a depth and at such an interval as to impart the wood overlaid board with flexibility. The product of the specific gravity and thickness of the flexible sheet is larger than the product of the specific gravity and thickness of the wood overlaid board, thereby positioning the center of gravity of the flooring material for building in the flexible sheet.