We've got this shower that's not all that old, maybe 7 years. Same tile all over the bathroom, it seems the grout used is efflorescing here and there - getting white in places that I've had to clean with acid... so I am thinking bad grout all over. But, on the side of the shower in the dry zone, and oddly only there (not in the WET areas) it seems the side tile is departing, I'd say 4-5mm off... I figured it could possibly be pushed out by.... guessing: bad grout/mortar or water infiltration/swollen wood ? (more logical)... the thing is I checked, there are zero grout defects inside the shower on that "bench" that would allow water inside that structure.. That's outside the glass too, so furthest away from any water if there was any. Also there is zero water ever coming out of that "crack area", none at all. Just the tile that appears to want to make a break for it all by itself...
What do you think it may be ? I'm game to trying to take it out by dremeling the grout or something, but I'd like some guesses from people who know tile more than I do (basically everyone) ;-)