On 2008-03-30, pkmicro wrote:

Should I use grout or caulk between the Bath Tub and the new
Porcelain tiles? TIA

That depends. Caulk is flexible, which is good at the joint between
two dissimilar materials that may move differently. Grout, in my
experience, is good because it doesn't support mildew growth as much
as caulk does.

So if your bathtub is acrylic or steel, it will move too much for
grout, so use the caulk. If your bathtub is cast iron, which is
pretty rigid like your tile, you can use grout, and it will be easier
to clean. If it develops a few small cracks, you can seal those with
a very tiny amount of caulk--don't cover the surface of the grout with
caulk, or it will defeat the advantage of the grout.

Cheers, Wayne