Hi everyone,

We had a shower completely torn out to the studs and replaced with a marble hex floor and ceramic wall tiles. It was completed mid-September and due to other reno's throughout the house, we did not move in nor turn on the water in the shower until mid-December. The tile coloring looked fine until the shower was used and it was wet.

I've read through nearly every thread here closely matching my situation and am hoping you can comment on this installation specifically. From those threads, I've pulled out some questions I've sent to my contractor (below). Before the install, the tiler warned us about the flatness of our wall tiles, so we replaced them with higher quality ones at his suggestion. He made a similar suggestion and we made a similar replacement for another shower in the house. He did not warn us about the quality of, nor the use of, marble for this shower floor.

I know that the installer used the full Schluter system - including the sloped pan - we still have the box he left behind. From those other threads, I've gathered that the tile has absorbed water and there's a possibility that an improper slope from the corners and outside edges to the drain might be causing pooling that is causing the porous tile to absorb the sitting water from beneath. Does the fact that the discoloration is not happening around the drain rule out clogged weeping holes and point to the lack of sufficent slope? The corners where the floor meets the wall are grouted.

What answers or actions should I be expecting of him and would be acceptable in your opinion? Is it possible that this wetness could be happening with a properly installed Kerdi system that's fully waterproof with no chance of mold or leaks in the future? We're fine with inconsistent "petina-ing" over time, but we're very concerned about mold, leaks, and bigger problems down the road.

Here is the email I sent to the contractor - awaiting his reply:
"We moved in to the house over the weekend and started using the master shower. After the first use, we noticed inconsistent drying of the tiles. I've attached photos taken 24 hours after the last use.

While we're fine with the inconsistent colouring/aesethic of the tile, considering the material we chose, we're concerned if trapped water in these areas is causing the absorption from underneath. If there is water pooling there and not draining properly, we're afraid of longer term mold and leaking issues.

We know you used the Schleuter system, but can you describe the installation process from the subfloor up to the tile, including the materials used, the slope specs, the results of the flood test, and the thinset and grout choices?

Also - as there are a couple schools of thought on this - why do you prefer to use grout at the change of planes versus silicone?

Obviously, I've done a bunch of reading on this type of situtation as I laid awake at night worrying about the impact of this install

We're looking forward to your professional assessment here and your thoughts on next steps."