For removing old surface coatings and leveling uneven floors use 20 grit. For intermediate sanding of floors following rough sanding use 36 grit. For intermediate sanding of floors following rough sanding or initial sanding of moderately worn floors use 40 grit. For finish sanding of all floors prior to applying new coatings or light sanding between surface coatings use 60, 80 or 100 grit.
