Shower Problems
Cracked grout and loose tile: what it is telling you
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Short answer
Cracked grout in a corner is usually a movement joint problem and can be fixed. Cracked grout across a field, hollow-sounding tile, or tiles that move are signs the tile has lost its bond or the substrate behind it is wet — and those are rebuild conversations, not regrout conversations.
Key takeaways
- Change-of-plane corners should be flexible sealant, not rigid grout.
- Tap-test the field: a hollow ring means the tile is no longer bonded.
- Grout is not waterproofing; regrouting a leaking shower hides the symptom.
- Efflorescence or persistent damp smell points to water inside the assembly.
- One loose tile can be repaired; a pattern of them cannot.
Corners crack because they move
Wall-to-wall and wall-to-floor joints move seasonally. Filled with rigid grout, they crack; filled with a flexible sealant, they flex and stay closed. A cracked corner on an otherwise sound shower is a maintenance item, and raking out the grout and resealing it correctly is a real fix.
Field cracks and hollow tile
Run a knuckle or a coin across the tile. A solid tap means good coverage behind it; a hollow ring means voids. Widespread hollow tile, or grout cracking in straight lines across the middle of a wall, means either poor mortar coverage or substrate movement. Regrouting will not change either one.
- Tiles that shift under thumb pressure: bond failure
- White chalky deposits at grout lines: water is moving through the assembly
- Soft or spongy spots at the shower floor: substrate saturation
- A musty smell that never leaves the room: water is sitting somewhere it should not
What to do next
- 1Photograph the cracking and note whether it is corners or field
- 2Tap-test the walls and floor and mark hollow areas
- 3Check the ceiling or wall below for staining if there is a room underneath
- 4Get an assessment before spending money on grout that may be treating a symptom
We will tell you when a shower can be repaired. We would rather do an honest small job than sell a rebuild that the shower does not need.
Frequently asked questions
- Will regrouting stop a leak?
- Not if the leak is behind the tile. Grout is a filler, not a waterproof layer. Regrouting can help a sound shower look and shed water better.
- Can you match old tile for a repair?
- Sometimes, if there are spares or the line is still produced. This is why we leave surplus tile with every project we finish.
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