As stated above if the floor is installed over a wood substrate and not placed in a staggered pattern with gaps and not fastened properly floors with ceramic tile installed over them can squeak.
Crunching floor tiles.
As long as the tile does not break under 250 pounds of pressure the tile is considered to be compliant with these standards.
In this test floor tiles are run through a machine that exerts loads on an unsupported 1 inch square area.
As a general rule tiles larger than 12x12 inches should have mortar applied to the back of the tile as well as the floor to help ensure adequate coverage.
In these cases you must grind down the ceramic floor tiles so that they fit around these objects.
Voids in the mortar under the tile allow the tile to flex and crack.
I have owned it since 2012.
Most tiles comply with astm c648 breaking strength standards.
Grinding ceramic tile can be tricky since the hardness is similar to glass and it can crack.
But the brittle nature of tiles and the constant foot traffic means that the tiles are likely to crack at some point.
However there are steps you can take mitigate tile cracking.
Installing ceramic floor tile is fairly simple until you reach the edges of the room or fixtures such as cabinets pedestal sinks and toilets.
Most tiles meet the 250 pound minimum.
Many of the causes of squeaking popping and crunching sounds that come from the flooring system are avoidable.
Ceramic floor tiles especially larger tiles need an even distribution of mortar underneath them.
My house was built in 1956.
There is a almost unnoticeable bulge where one of the tile comes up.
It takes combined collaboration between the builder the end user the involved manufacturers and the flooring professional to be able to mitigate the causes.
It is the original tile with no signs of repair or cracks in the tile or grout.
There is an area about 15x15 inches that makes a crackling noise when you step on it.
If the floor has too much deflection that grout can crack among other things.
Recently i noticed that a few of the floor tiles in the kitchen make a crunching sound when walked on.
So it is hard to say if a crunching sound is a squeaking sound or what.
Reinforcing your floor will make for a more solid and level surface.
On closer inspection i can see that the tiles are moving very slightly against the grout which is causing the sound.
In a case where cracking is minimal or has occurred in only a small number of tiles and or the floor is in a location where aesthetics don t matter to you the easiest most inexpensive solution is diy patching.