Tile on Tile: What You Need to Know Before You Start Tiling Over Existing Surfaces
Tile-on-Tile: What You Need to Know Before You Start Tiling Over Existing Surfaces
Tiling over existing tiles—known in the trade as ‘tile-on-tile’—can be a time-saver, but it’s not as simple as it sounds. In Episode 11 of the ARDEX Answers Podcast, Monique Fenech is joined by James Bradford, ARDEX Technical Services Advisor, to unpack the dos, don’ts, and must-knows of this popular installation method.
What is Tile-on-Tile?
As the name suggests, tile-on-tile installation involves laying new tiles directly over an existing tiled surface. It’s a method that can save significant time and labour by eliminating the need to rip up old tiles. But there’s a catch: it’s not appropriate in all situations, and getting it wrong can lead to adhesive failure, water issues, and more.
When is Tile-on-Tile Suitable?
James notes that tile-on-tile can be successful when the original substrate is sound, solid, and not drummy. If tiles are lifting, cracked, or if there are movement issues in the substrate, it’s best to remove them entirely. If you’re unsure, the old ‘tap test’ can help assess if there are hollow spots beneath the tiles—hollow = trouble.
Surface Prep is Crucial
One of the most important steps is thorough cleaning. Tiles must be free of oils, grime, and soap residue. Etching the surface or applying a bonding primer may be needed to ensure new adhesive can properly grip the old surface. ARDEX P4 Primer is a go-to solution, especially designed to promote adhesion to smooth, glazed surfaces like existing tiles.
The Right Adhesive for the Job
Not all adhesives are created equal. When tiling over tiles, you’ll want to use a high-performance polymer-modified cement-based adhesive. ARDEX X 77 or ARDEX X 18 are excellent choices, providing strong initial grab and long-term bond strength.
What About Waterproofing?
If you’re working in a wet area and the original waterproofing integrity is unknown, it’s risky business. As James advises, always ensure the waterproofing system is intact or re-apply it if there’s any doubt. Failure here could mean extensive damage later, so it’s not worth cutting corners.
Final Thoughts
Tile-on-tile installation can be a practical solution—but only when done correctly. Sound substrate, good prep, the right primer, and adhesive choice are non-negotiable. When in doubt, always consult ARDEX’s technical datasheets or speak to the team directly.
Need support? Call the ARDEX Technical Services team on 1800 224 070 or check out our training sessions at the ARDEX Academy.