"RicodJour" wrote:

John wrote:
I bought a load of chinese granite "Bianco Cordo" about 1 cm thick 30 cm x 60 cm.

It's polished white/grey granite. They are placed outside where rain, frost and
temperature ranges from -20 (january) to +30 (right now). After having set some
plates I noted the granite plane color change slightly. It was probably mortar
moisture seeping from below. The polished top did to get any moist. Next day the
discoloration has disappeared. It probably just evaporated since its +30
centigrade now.

Will there be problems in winter? Will the granite crack from frost changes? I
thought granite behaves well in winter.

I am not familiar with that particular stone, but all stone reacts
differently. It's not just whether it is granite or not. I know that
some of the Chinese marble has to be installed with epoxy thinset and
not regular as the water content messes it up. Marble is not granite,
but my point is the same. Ask the supplier.

The darkening from the moisture is to be expected in any stone and most
obvious in the lighter colored ones.

R

The temporary discoloration was hadrly noticeably and it went away quicky so that
was not a problem. I don't want the stones to crack, however. I've spent enough
time in fixing botched jobs from wrong materials.

The seller of the stones was not sure. They too knew anou the marble. Same thing
with some Italian marbles: you have to use same color mortar to be safe.