Help! Tile at bottom of Shower changing color!

[blayscue]

We had my master bath remodeled several years ago, and we recently found that one of the white tiles at the bottom of the shower has turned from white to light gray. I assume that is a water issue. I do know that the walls had backer like hardie board and then were painted with a red waterproof membrane. The shower pan has a blue liner and was then poured. It has some slope to drain, and does not have standing water. What should my first step be in determining and fixing the problem? I will post a picture. Do you think it will be possible to fix the issue without completely redoing the entire shower?

[blayscue]

Any feedback would be most appreciated!

[rmckee84]

There can be a number of causes.
If the tile is cut, I've seen where water will wick up through the tile.
It could be a defective tile
There could be an underlying issue in the wall.
The only way to remedy what you have is to pull it and replace with a new tile. When you remove the old tile you can inspect the area behind it and make sure there isn't any issues.

[MAPEI - Technical Service]

Is the corner between the wall and the floor grouted or does it have caulk in it? If caulk is present, is it caulk over grout or is the caulk filling the joint?

[blayscue]

grout everywhere with silicone caulk over grout. I do believe, though, that the bottom row of tiles sit below the floor tile just a bit instead of meeting the floor.

[rmckee84]

If that's the case odds are the tile is wicking the water and that's causing the discoloration.

[blayscue]

So, if it is the issue of the tiles sitting slightly below the floor surface, I supposed that I could just have that bottom row replaced all the way around and get them where they meet at a grout line instead of going below. I probably do have enough tiles to replace that complete bottom row, and when we tear out, we can see if there is any issue behind the tile. I have seen some cracks in the grout on the floor of the shower also. No cracked tiles, though. Just hairline cracks in the grout. I will probably want to have the floor re-grouted, I would think.

[blayscue]

I just wonder if I have a shower pan problem...yikes.

[rmckee84]

I'd start with just the discolored tile and go from there

[cx]

Welcome, Gracie.

Originally Posted by Gracie

The shower pan has a blue liner and was then poured.

Do you know if there was any slope created under that liner?

[jadnashua]

It sounds like the liner is flat on the floor. IF that's the case, the shower should NOT have passed any plumbing inspection when built...plumbing codes require the waterproofing to be sloped to the drain. FWIW, neither the tile nor grout are considered the waterproofing. What will happen is that a very small amount of moisture will get beneath the tile. It may not evaporate depending on the use pattern, and then can start to accumulate since there's no slope on the liner to guide it to the drain.

Painting a waterproofing on the walls, preventing moisture from being able to get out that side, but sticking in the wet mudbed, will allow moisture to wick up into the wall. If there's not a moisture barrier behind the walls, that can be a problem, too.

[blayscue]

Thank you all for the feedback. I don't know if there was any slope created for the actual liner. It could very well be flat on the floor. I honestly don't know. I know that the actual concrete or mud or whatever of the shower pan has a slope and was painted with the red guard stuff as well as the hardie board walls. I do see some mildew/mold in the grout line/silicone joint where the discolored tile meets the floor. This all leads me to suspect that everything is coming up from a pan problem. But, as mentioned before, we will begin with tearing out the offending tile and go from there.

[blayscue]

I do know that mastic Was NOT used on the walls which is good. I just feel like this is a major kettle of fish if it is a pan problem because I have that granite bench in the shower which is a continuation of the tub granite and there is granite that comes down the front of the bench and sits on the shower floor.

[cx]

Originally Posted by Gracie

I know that the actual concrete or mud or whatever of the shower pan has a slope and was painted with the red guard stuff as well as the hardie board walls.

Very bad to have both a traditional pan liner and a direct bonded waterproofing membrane in your shower receptor, Gracie. Especially if there is no pre-slope under the liner.

You may be able to leave some of the very water molecules that you showered with to your great, great grandchildren.

My opinion; worth price charged.

[Davy]

Lets back up a little. It doesn't matter if the floor tiles go to the wall tiles or if they go under the wall tiles. If the preslope, pan and mud bed is installed correctly, it all works. Also, it doesn't matter if the bottom row are cut tiles or full tiles. Again, if the floor is done correctly, it will work fine. I would replace that one tile to start with. I don't see any reason to replace the whole bottom row at this time.

What Cx said about having two membranes. Not a good idea.