Grout cracking in shower corners
Urgency
3/5
Honest verdict: this one's worth a pro$150–$600Typical repair cost
Likely causes, most common first
- Corners are movement joints — grout is rigid and cracks where planes meet; it should have been silicone
- Normal seasonal structure movement flexing the tile planes
- If cracking is widespread mid-wall too: failing substrate or waterproofing behind the tile
Do this right now
- Stop water from hitting the cracked corner directly
- Don't re-grout corners — it will crack again by design
DIY or call a pro?
Corner cracks alone: a pro rakes them out and silicones them in an hour or two. Cracks spreading across walls, loose tiles, or a spongy wall mean water is behind the tile — that's an inspection, not a tube of caulk.