Generally hairline cracks in the concrete will not present an issue to the tile floor above.
How to keep floor tiles from cracking.
In many cases the crack is not the result of an inferior tile.
Crack isolation membranes allow for slight shifts or movement of the floor that lies underneath the tile allowing it to move independently without moving and cracking the tiles above it.
However there are steps you can take mitigate tile cracking.
But the brittle nature of tiles and the constant foot traffic means that the tiles are likely to crack at some point.
Take these precautions to prevent tile cracking in the future.
For a concrete subfloor the most effective thing to do is add steel reinforcing bars when the concrete slab is poured.
This could include a framed floor that has too much bounce or improper isolation of the tile from the subfloor whatever that subfloor may be.
Cracked tile is usually a sign of poor preparation of the substrate.
Are you planning to have new tile floors installed.
How to prevent cracked tile.
Cracked tiles on floors and walls is a problem because it can be difficult to track down the source of the crack.
Reinforcing your floor will make for a more solid and level surface while repairing tiles with epoxy is an easy fix for single tiles that become cracked.
This is known as reflective cracking and it can be easily prevented by adding a crack isolation membrane during installation.
However cracks wider than 1 8 inch will eventually transfer to the tile it notes.
But how stiff is stiff enough.