We recently bought a new home and are going through fixing things and noticed one of the shower wall tiles near the bottom of the door was popping out. Removed it and not sure how to proceed to replace it. I assume I should fill in the hole with something, let it dry, replace the tile with mortar let that dry, and then grout but would appreciate any advice.
House is pretty old overall (1965) but shower looks in relatively good condition and I’m sure it’s newer than that.
Tile in question:
A few general shower: