On 2007-10-07 12:10:31 +0100, AJ said:

Hello All

I have some travertine mosaic tiles on my bathroom floor (Honed and
Filled) but some of them are appear to be disintegrating in that the
polished top of the tile has disappeared leaving a chalky abrasive
tile. Is this due to the fact that the tiler didn't seal them properly
and water ingress into the stone? Based on this should I clean them
down and seal again, including the good ones with an impregnator or
will the damaged ones just get worse??

The procedure would be to clean them thoroughly - Lithofin Wexa is
good for this - allow to dry thoroughly for at least 24 hrs. Then
apply a good quality sealer (e.g. Lithofin MN Stainstop) and leave that
for 24hrs as well.
Fill with the same shade of grout as has been already used and allowed
to go off for at least 24hrs. Finally apply two further coats of MN
Stainstop.




Also is it possible to get a nice polished finish using impregnator, I
have some large travertine tiles on the wall too and would like to get
a polished finish.

If it was honed then it will remain honed unless it's mechanically
polished by going through a series of polishings with ever finer grades
of abrasive. Normally that is done in the factory before shipping
and would be difficult to do in situ.

The sealer products are deliberately designed not to impart a different
finish to the nice honed original which is also why excess is wiped off
to avoid patches. You could try a colour enhancer product.
Lithofin do one of these as well and it should go on after the washing
stage. It will raise the colours and appearance, but won't make
something look polished that isn't.