Before I get started, let’s make one thing clear: I rent my current home, and hence don’t have an interest in dumping my own money into long-term fixes.
For background… my father was a ceramic tile contractor. An old-school one trained by Italians who knew how to install ceramic tile that would last many generations with no cracks in the tile or the grout. Yes, floating mortar bed on the floors. Mortar on the walls with metal lath. Etc.
My current home wasn’t done that way. In fact, it was done in the worst way, which guarantees problems in a fairly short period of time. All of the main living space was done in quarry tile (which I like; natural color all the way through the tile, inherent non-slip surface, not expensive). However, it was installed using mastic directly over plywood. No real tile man, young or old, would consider this intelligent. Mastic is not waterproof, and tile floors will be mopped or sponged clean. Plywood is flexible, tile and grout are not. The end result is tiles breaking free from the plywood, cracks in the grout, which then permits water to reach the mastic and accelerates the floor’s demise.
If this were my home, the solution would be to tear out the whole floor and replace it correctly. Modern method would be cement board, though I’d prefer a floating mortar bed. But this isn’t my home.
I have identified several loose tiles. A week ago I replaced 4 of them at the entrance to one of the bedrooms. Removed the tiles, removed the mastic, replaced the tiles and re-grouted. This week I replaced 6 in the center of the floor in a heavily trafficked spot. All had broken free of the plywood. Disconcerting to find that someone had attempted to repair this area before by just replacing the cracked grout with caulk. Ugh; doesn’t fix the problem, doesn’t hold up well to traffic, and the caulk on the edges of the tiles would prevent grout from ever sticking to it again. Equally disconcerting was what I found underneath: the trowel used for the mastic clearly was not a thinset trowel, the grooves were too thin. To aggravate things even more, the grooves in the tiles were laid in parallel to the grooves in the mastic. Umm, they’re supposed to be perpendicular.
If I ever meet the hack that installed this floor, I’ll be sure to chastise him. I can’t hold much against the homeowners, I don’t expect them to know the right way to install or repair ceramic tile. If I ever put tile in my own home in the future, I’m going to do it right.