GB477603A - An improved method of facing walls - Google Patents

Abstract

A method of facing walls consists in first applying a succession of cement-sand coatings, at least one of which contains a waterproofing substance, then applying by means of a spray a coating of cement and other materials, and finally in impregnating the surface formed by the last-mentioned coating with an insoluble precipitate. Alternatively, the wall may be faced by the application, first, of a sand-cement slurry, secondly, of a number of sand-cement coatings, at least one of which contains a waterproofing substance, and thirdly, of a cementitious composition containing a metallic soap, and the surface of the last mentioned layer is treated with alternate applications of soap and alum solutions. Three sand-cement coatings may be applied on to the layer of sand-cement slurry, and the proportion of sand in these three layers may be gradually increased. The slurry and the succeeding coatings may all contain a waterproofing agent, such as zinc palmitate, but this is an essential ingredient of the third sand-cement coating. Each coating, after the first, is applied before the previous coat is too hard to receive a thumbnail impression. The cementitious composition which is applied by spraying on to the last sand-cement coating may comprise 100 parts by weight of cement, 5 parts of calcium hydroxide, 10 parts of puzzuolanic earth, 2,5 parts of sodium chloride, ,06 parts of zinc palmitate or other metallic soap, and water. When this surface is quite dry, it is impregnated with an insoluble precipitate which may be effected by spraying on to the surface alternate applications of potassium oleate solution and alum solution. The final surface may be polished by hand or mechanically. Specification 422,051 is referred to.