"NSN" wrote in message
...

I have about 2000 sq. ft. of 12" Travertine tile in my home. Every
two or three years I have to replace at least 20 tiles because of
cracking. I am in California and as many of you know, we get quite a
few minor earthquakes yearly. We also get a major one every few years
which does not help the problem.

Originally, the tile was laid directly over the concrete slab with
thinset. When replacing the tiles I have been using a thin layer of
mastic, then a layer of roofing paper (black "tar" paper) and then
another thin layer of mastic. I had hoped that this would insulate the
Travertine from the slab. It does not . some of the tiles continue to
crack but at a slower rate.

I am getting ready to replace another 20 tiles. Does anyone have any
ideas as to how to secure the tiles in place yet allow some
flexibility to prevent cracking? I suspect that I might end up with
some cracking of the grout but I would rather replace the grout in
these areas than replace the entire tile.

Norm

It sounds as if the tile is not fully supported by thinset beneath, so that
walking breaks the partially supported tile. Travertine is an extremely
fragile limestone, but still I doubt that the cracks are in any way related
to earthquakes, unless the tiles reflect cracking in the slab beneath, a
problem of much greater import.