Grout in shower floor discolored - tile experts please weigh in!
Our shower floor was installed middle of last week and was grouted on Thursday. The grout color is a very light gray (Winter Frost - C-Cure), but after a day or so, the grout in the shower floor has taken on an inconsistent, discolored look. It is particularly darker around the drain and is covered with a white, chalky substance. The floor material is Calacatta marble. Unfortunately, the hex marble almost looks like something is eating away at the tiles, as the edges look jagged. This is getting worse over time and after a few days, it does not look like a brand new shower.
My contractor is off for a few days, but we have been researching this and came across a few older threads about inadequate sloping, weeping, and pre-sloping. Our contractor subbed out the hot-mopping and tile installation, and I would expect we will need to meet with all of them to determine what is causing is.
But based on these photos and the fact that the shower has never been used (the shower head was installed on Saturday afternoon and it was turned on briefly to make sure it worked properly), does anyone have any thoughts as to what could possibly be causing this?