Grinding

When grinding of a concrete floor is specified, start it after the surface has hardened sufficiently to prevent dislodgement of aggregate particles and continue it until the coarse aggregate is exposed. The machines used should be of an approved type with stones that cut freely and rapidly. Keep the floor wet during the grinding process, and remove the cuttings by squeegeeing and flushing with water.

After the surface is ground, air holes, pits, and other blemishes are filled with a thin grout composed of one part No. 80 grain carborundum grit and one part Portland cement. Spread this grout over the floor and work it into the pits with a straightedge. Next, rub the grout into the floor with the grinding machine. When the fillings have hardened for 17 days, the floor receives a final grinding to remove the film and to give the finish a polish. Then remove all surplus material by washing thoroughly. When properly constructed of good-quality materials, ground floors are dustless, dense, easily cleaned, and attractive in appearance.