Applying new tile directly over existing tile is a method that begins with thorough preparation of the original surface to ensure proper adhesion and a durable finish.
Surface Preparation: The Critical First Step
Before you can lay new tiles, the existing tile surface must be properly prepared. This is the most crucial stage to guarantee the success of your new tile installation.
Cleaning the Existing Surface
According to preparation guidelines, the initial step in the tile-over-tile process is to clean the surface with a multi-purpose cleaner. This removes dirt, grime, grease, and any residue that could prevent the new adhesive from bonding effectively to the old tiles. Ensure the surface is completely dry after cleaning.
Inspecting and Repairing Existing Tiles
A vital part of preparation involves checking the stability of the existing tiles. You need to inspect the adhesive by lightly tapping on each tile with a hard object. Listen carefully to the sound produced. If it sounds hollow, that tile will need to be removed because the underlying adhesive is no longer sufficient. Any loose, cracked, or damaged tiles should also be removed and the area patched to create a level, stable base.
Steps for Applying Tile Over Tile
Once the surface is clean, dry, and repaired, you can proceed with the tiling process.
- Apply a Suitable Primer: A bonding primer designed for tiling over non-porous surfaces is often recommended. This enhances the bond between the old tile and the new adhesive.
- Mix and Apply Adhesive: Use a high-quality modified thin-set mortar specifically formulated for tiling over existing tile or non-porous surfaces. Apply the adhesive evenly using the correct size trowel for your new tiles.
- Lay New Tiles: Begin setting your new tiles into the wet adhesive, following your desired layout. Use tile spacers to maintain consistent grout lines.
- Grout the Tiles: Once the adhesive has fully cured (check the manufacturer's instructions for drying times), mix and apply grout into the spaces between the new tiles.
- Clean and Seal: Clean off excess grout from the tile surface. After the grout has cured, apply a sealer if necessary (depending on the type of grout and tile used).
Following these steps, with particular attention to the critical surface preparation, allows for a successful tile-over-tile installation.
