How to Restore Terrazzo Floors

In this video, This Old House host Kevin O’Connor heads to Del Ray Beach, Florida, to restore terrazzo floors.

Steps:

1. Mask the lower 24 inches of the room’s walls with plastic sheeting.

2. Install 30-grit diamond disks onto an electric floor-grinding machine.

3. Add steel weights to the machine to increase the downward pressure on the floor.

4. Wet the floor with a garden hose, then start grinding.

5. Pass over the floor four times in an east-west direction, and then four times in a north-south direction.

6. Release more water from the reservoir on the machine, as necessary.

7. Use an angle grinder to smooth the floor around the edges of the room and any other places the grinding machine couldn’t reach.

8. Install slightly finer 40-grit disks to the grinding machine.

9. Remove a little weight from the machine, then grind the floor again.

10. Patch any holes in the floor by first enlarging the holes with an electric chipping hammer.

11. Next, mix polyester stone adhesive with the marble chips.

12. Fill each hole in the floor with the adhesive.

13. Allow the adhesive to harden, then grind each patch smooth using an angle grinder fitted with 40-grit sandpaper.

14. Smooth the patches again with 120-grit sandpaper.

15. Wet the floor with a sponge, then polish the patches with an angle grinder and diamond pad.

16. Continue grinding the floor moving through eight more progressively finer grits of diamond disks.

17. Remove a little weight each time you switch abrasives, and grind the final pass with 3,500-grit disks.

18. Polish the floor with a planetary polishing machine.

19. Sprinkle an acid-based compound polish onto the floor, then polish the floor with a wet polisher. Pass back and forth over the floor, making 20 passes over each row.