Sand the surface of the tile with a belt sander and 180-grit paper. The sanding won't remove the existing glaze completely, but will dull and de-gloss it, turning it slightly opaque.
Mix 1/2 cup of TSP power with about a gallon of warm water. Thoroughly scrub the tile with a stiff scrub brush. Mop-rinse it. Let it dry for at least 24 hours.
Brush floor-grade polyurethane over the whole floor, starting in the far corner of the room and working your way out toward the door. Brush it on in a thin, smooth coat, with the brush strokes all going in the same direction. Let it set overnight.
Use your 250-grit sandpaper to hand-sand the polyurethane, buffing it just enough to remove the shine so the next layer will adhere.
Wipe up the dust. Apply a second coat of polyurethane in the same manner as the first. Let it dry overnight, hand-sand it, and brush on a third layer. Let the third layer dry for two to three days before using the floor.
Things You Will Need
- Belt sander
- 180-grit sandpaper
- TSP (trisodium phosphate) cleanser
- Stiff scrub brush
- Floor-grade polyurethane
- 250-grit sandpaper
- If you don't like the color of the tiles, now is the time to change it. After you de-gloss and scrub the tiles, but before you layer them in polyurethane, apply a sealing primer and then your topcoat of paint, in two or three layers. Gloss over the paint with your polyurethane to seal it in.