Most tiling failures come from a small number of avoidable mistakes: laying on a damp or uneven substrate, dab-fixing instead of full back-buttering, forgetting expansion joints outdoors, using gypsum in wet zones, or neglecting waterproofing. Knowing them is already avoiding them — and knowing how to spot a botched installation.
- Cause #1
- Uneven or damp substrate
- Cause #2
- Dab-fixing (hollow sounds)
- Cause #3
- No expansion joints
- Wet zone
- Gypsum instead of cement
- Pool/shower
- Waterproofing neglected
The substrate: half the problems
Laying on a substrate that is still damp, dusty or uneven dooms the work: delamination, hollow sounds, lippage. A sound, dry, laser-levelled substrate is the non-negotiable base. It shows little on the quote, but this is where the lifespan of the installation is decided.
The bond: full, never dabbed
Dab-fixing (a few blobs of adhesive under the tile) leaves voids: water settles in them, the tile sounds hollow and breaks under load. Full back-buttering — combed adhesive on both substrate and slab back — is the rule, especially for large format and outdoors.
Expansion joints and waterproofing
Outdoors and on large areas, the absence of expansion joints guarantees cracks in time. In wet zones, laying on gypsum (which swells with moisture) or skipping waterproofing brings delamination and leaks. These are savings that cost dearly later.
Tiles that sound hollow when tapped, lippage that catches the light, uneven joints, outdoor cracks, or gypsum visible in a wet zone. These are the signs of a neglected substrate or bond.
