Shower floor grout crumbling/disappearing with white buildup — cosmetic issue or water underneath?
Hello,
Looking for some advice before I start tearing into this.
This is the floor of an open shower in my bathroom. The grout between some of the tiles is crumbling/disappearing, and there’s a white chalky/crusty buildup that I can’t really scrub off completely. There’s also a bit of green discoloration in places.
The tiles currently seem mostly solid and not obviously loose, but I’m concerned this could mean water is getting trapped underneath.
Questions:
Does this look like typical grout failure/efflorescence?
Is this usually just a regrout job, or can it indicate waterproofing/shower pan problems underneath?
What’s the proper way to clean this before repairing it?
Would you regrout with normal grout or epoxy grout?
Any signs here that suggest a bigger issue?
Photo attached.
Thanks in advance!