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