Thanks Charles, Roger and Wayne for your comments. I did not do the
original installation. Most of the cracking occurs over cracks in the
slab in the hallway . The cracking is not totally related to the
quakes but they sure do not help. When one has a 50' X 8' length of
slab in a home where the chandeliers sway and the pool water sloshes
around during a quake, the slab will flex to some extent. I thought
that I would prevent this from happening and had the builder use 3/8"
re-bar throughout the slab. It probably helped but not enough. Too
much work removing all the tile so I am stuck with periodic
replacement. I have to use sanded grout again to match the original.
I am stuck with what I have. At this point my only hope is that I can
find a way to reinstall the tile without having it bond in a rigid
fashion to the underlying slab. The cracks are definitely not from
foot pressure .. they are from cracks in the slab. What I really need
is rubberized Travertine ;-)

Norm



On Thu, 11 Dec 2003 02:38:36 GMT, "wayne" wrote:

You don't mention if the cracking is in the sam eplace or different or if
the thinset or tile underneath is cracked. it may just be that you did a
poor install job in the the concrete was not flat and the tile is craking
due to stress not earthquakes. hve you niticed cracka just after small
quake?

Wayne


"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