How to lay new wall tile over old tile

Tiles can be installed over tiles as long as the underlying tile is in good condition. Before considering whether to install tile over tile, inspect the original installation for cracks, loose tiles, and water damage. If the underlying tile is not stable, the tile you lay on top of it will bend, crack, or fall off the wall over time. A common problem faced by tile installers is that the tiles are pulled down by the force of gravity before the adhesive sets. This is usually due to the adhesive not being mixed properly. Follow the manufacturer’s instructions closely to ensure proper mixing.

Instructions

Preparing the surface

1. Clean the tile surface you are laying the tiles on.

2. Sand the tile surface to facilitate adhesion of the new tile to this surface. Use a sander with 80 grit sandpaper to roughen the tile surface.

3. Sweep and clean the surface to remove dust caused by sanding.

Lay the tile

4. Find the exact center of the wall. To do this, use a tape measure to find the center of each side of the wall and draw a perpendicular line from the edge across the wall. At the intersection of this X and Y axis is your center mark.

5. At the base of the wall, lay a row of loose tiles from the center mark to the end of one of the walls or the installation area. Be sure to insert two spacers on each tile for a proper layout. Most likely, you will not be able to place the last tile between the edge of the wall and the row of tiles. This is good; leave that out for now.

6. Measure the distance from the last full tile to the edge of the wall or installation area. Keep this distance in mind for later.

7. Lay another row of loose tiles from the center of the wall in the opposite direction.

8. Measure the distance from the last full tile to the edge of the wall or installation area.

9. Move the vertical center line to divide the distance between these two measurements. For example, if the space on the left side is 8 inches and the space on the right side is 4 inches, move your line 2 inches to the left so there are 6 inches on each side.

10. Repeat this process for the horizontal center line. However, because you’re installing wall tiles, you won’t be able to rest them on the floor like you did with the vertical centerline.

11. Place a chip on the center mark and hold it in your hand.

12. Lay your tile spacer on top of the tile and make a mark on the top of the tile spacer.

13. Place the bottom of a tile at this mark and repeat the process. Lay out a tile spacer and make a mark.

14. Measure the distance from the last full tile to the top of the wall. Mark this distance for later use.

15. Repeat the same process down the wall from the center mark.

16. Divide the difference between the two measurements and adjust the center line as needed. The intersection between these two fitted lines is your center tile mark. This divides the wall into four rooms. You will tile these rooms one at a time starting from the center mark.

Preparing the Thinset

17. For half the amount of water recommended by the manufacturer in the 5 gallon bucket.

18. Empty half the bag of thinset into the bucket.

19. With your high-power grinder/drill set to low speed, with the mixer attached, mix the water and thinner.

20. Add the remaining water and thinset in small batches while mixing, until all of the water and thinset have been added.

21. After mixing thoroughly, allow the thinset to sit for 15 minutes so that the adhesives it contains can fully incorporate.

Placing the Tile

22. Scoop out a portion of thinset from your bucket with the half-inch trowel.

23. Start at your center mark and spread the thin layer over the old tile. Tilt the trowel at a 30-degree angle and spread the thin layer in large, half-arc strokes. The edge of the trowel should not drag along the tile below, but should press the thin layer against the underlying floor.

24. Roll out several square feet of thin sheeting. Do not cover the entire floor.

25. Place a tile on your center mark, in the corner of the room on the wall you are starting with. Do not press the tile down into the skim coat, but give it gentle, even pressure so that it adheres to the skim coat.

26. Lay a tile next to that one and insert two tile spacers between them. Lay the tile close enough that you don’t have to move the tile excessively to get it flush against the spacers.

27. Continue this process of spreading small patches of thinset, laying tiles and inserting two spacers.

28. Cut tiles that butt against walls or other obstructions with the wet saw. When measuring these spaces, remember to account for the distance your gasket (and spacers) will occupy in the area. The joint is the area between the tiles that the grout will occupy.

29. Continue around the room, completing the rooms marked by the center line marks.

30. When finished, allow tiles to set for 48 hours, unless a quick-dry skim coat was used, in which case refer to manufacturer’s cure time.

wall grout

31. Mix grout according to manufacturer’s instructions.

32. Scoop out a cup-sized portion of grout with the cushioned grout trowel.

33. Start grouting from a corner of the room that allows you to work toward the door. This will prevent you from getting trapped in the room and having to walk on the grout.

34. Spread the grout diagonally across the joint. Hold the float at a 30 degree angle and watch out for gaps in your coverage.

35. Use a damp grout sponge to wipe any excess grout diagonally across the joint. No matter which diagonal direction you wipe the grout, just don’t sponge directly across the grout joints just yet. Rinse the sponge frequently and be sure to properly remove any laitance on the tile surface.

36. Run the grout sponge along the joints to sink and shape the grout into the joint.

37. Allow grout to dry according to manufacturer’s specifications.