How to Tile Over Existing Tiles

An old tile installation

Whether you are moving into a pre-owned home or are simply tired of looking at an older tile installation day in and day out, installing new tile can be the best option for sprucing up a floor. And while the most common way to install a new tile floor is to completely remove the old tile and go back down to the original substrate, there are occasions when you may tile over old ceramic tile or natural stone. Tiling over existing tile can save a lot of time and resources, provided the old installation is structurally sound.

Things You'll Need

• Dust mask
• Safety glasses
• Earplugs
• Belt sander with carbide or diamond sand belts
• Latex-modified thinset mortar
• Notched trowel
• Tile spacers
• Tape measure
• Pencil
• Tile cutting board
• Tile wet saw

Instructions

1. Check the previous installation for structural stability. Look for cracks in the grout. Tap lightly on the floor with a hammer or other hard object and listen for hollow echoes. Understand that any loose pieces or areas where the tile may be cracking out need to be patched by removing the individual pieces of tile and filling the area with thinset mortar at least 24 hours before installing new tile.

2. Purchase the new tile. Choosing tile that is the same size as the existing tile makes installation considerably easier and less time-consuming because you can use old grout lines as reference points rather than having to create a new layout. Realize that you can also use tile that is half the size or twice the size and still use the previous grout lines.

3. Put on the safety gear. Run the belt sander over the entire surface of the previous installation. Understand that in order for the thinset mortar of the new installation to bond with the surface of the old tile, you must adequately roughen the surface of the old tile. Pay special attention to corners and make sure you scratch every inch of the surface; any patched areas filled with thinset mortar do not need to be sanded. Completely remove all of the dust and debris when you are finished.

4. Apply the latex-modified thinset mortar to the floor. Apply firm pressure when spreading the thinset to ensure that you burn it into the scratched surface of the existing tile. To achieve complete coverage, work the thinset in all directions as you smear it. Apply just enough to work with a few tiles at a time until you are comfortable with your pace.

5. Apply firm pressure as you place each individual piece of tile into the bed of thinset mortar. Move each individual piece of tile slightly in all directions to complete the bond between thinset and tile, and use tile spacers between each piece.

6. Make any straight cuts along the walls or other parameters with the tile cutting board. Utilize the tile wet saw to make cuts around corners of any cabinet, doorway, floor vent or toilet. Dry each piece of tile completely with an old towel or a rag before setting because moisture can prevent the thinset mortar from bonding with the tile.

Tips & Warnings

• A typical 12- by-12-inch tile requires a 3/8-inch notched trowel. Larger tiles require a larger notch, and smaller tiles vice-versa.

• Tile spacers come in a variety of widths; the size you choose depends on how wide you want your grout joints to be.

• All materials and tools can be purchased or rented from your local home improvement store.

• Always wear protective gear when working with power tools of any kind.

Resources

• National Tile Contractors Association