Why Tiles Crack or Lift — and How to Prevent It
The Tile Is Almost Never the Problem
When a tile cracks or lifts, the instinct is to blame the tile. It is almost always wrong. Porcelain is one of the most stable surfaces there is — dense to EN 14411, group BIa, absorbing ≤0.5% water, so it does not swell, shrink, or move with Ghana’s humidity. The panel is the victim, not the culprit. The cause is nearly always beneath it or around it. Understanding the real causes is how you avoid paying twice.
The Three Real Causes
1. Voids — Not Enough Mortar Under the Tile
If a tile is bedded on less than full mortar coverage, the unsupported areas are weak points. Walk on them, drop something, and the tile cracks; tap them and they sound hollow. The fix is method: ≥95% mortar coverage per ANSI A108, achieved by notch-trowelling the floor and back-buttering the tile. A fully supported tile has nothing to crack into.
2. Substrate Movement
If the floor beneath flexes or moves and the tile is bonded rigidly to it, the stress goes straight into the tile. A deflecting deck, a green (uncured) screed, or a substrate that was never flat all transmit movement upward. The answer is a sound, flat, cured substrate and a deformable adhesive (ISO 13007 C2 S1 / ANSI A118) that absorbs minor stress instead of passing it to the tile.
3. A Missing Movement Joint
Tiles and substrates expand and contract with temperature — and a sun-facing floor or terrace in Accra moves more than people expect. With nowhere to expand, the field tents, lifts, or cracks. The prevention is designed-in movement joints per TCNA EJ171: perimeter joints and field joints that give the floor controlled places to move.
How to Read the Symptom
| What you see or hear | Likely cause | Prevention |
|---|---|---|
| Hollow sound underfoot | Voids / low coverage | ≥95% coverage, back-buttering |
| A single cracked tile | Void plus impact or point load | Full support beneath every tile |
| A line of tiles tenting up | Missing movement joint | TCNA EJ171 joints designed in |
| Lifting across a sunny area | Thermal movement, no joint | Movement joints, deformable adhesive |
| Cracks tracking a wall or column | Substrate movement at a junction | Sound substrate, perimeter joint |
Why “Cheap” Tiling Cracks
Failures cluster on jobs where the method was skipped to hit a number — thin mortar coverage, no movement joints, tiling over an unlevel or uncured slab. The tile looks fine on day one and fails months later, long after the bill was paid. Done to standard, the same tile lasts decades. The difference is never the tile; it is the discipline beneath it. This is exactly why we survey first and quote on survey — and why our substrate preparation and large-format porcelain work is built on the method, not the shortcut.
The Standards That Prevent Failure
- ANSI A108 — installation method, flatness, and ≥95% coverage.
- ANSI A118 / ISO 13007 — a deformable C2 S1 adhesive that absorbs substrate stress.
- EN 14411 (≤0.5% absorption) — a stable porcelain body that is not the failure point.
- TCNA EJ171 — movement joints that give the floor somewhere to go.
If a Floor Is Already Cracking
A hollow, cracked, or lifting tile is a signal, not a cosmetic issue — and it usually spreads. Tilers Ghana diagnoses and repairs failing floors across Accra, Tema, and the rest of Ghana, and has done so to standard since 1976. Call +233 20 531 3333 for a repair survey, and we will find the real cause — and fix it so it stays fixed.