was the tile sealed?

You have my sympathy!! So tough to have your hard work and decisions take on a life of their own!! Is it possible your discoloration is on the surface?

We have a narrow Carrara sill on a window thatâÂÂs in our shower⦠gets hit with water/soap/shampoo⦠and even got sprayed with a cleaner I wouldnâÂÂt normally use on marble⦠Totally fine, looks brand new.

But we have a marble shelf area at the end of the tub⦠above head level, above water spray⦠never been cleaned with anything, just wiped off with paper towels I dry mirror with⦠and itâÂÂs developing discolored spots on the edge.

ItâÂÂs not a big deal, since itâÂÂs a small area and I am the only one neurotic enough to notice, but itâÂÂs a total mystery.

Here is a link that might be useful: Our vintage-inspired bath.

Yes the marble is sealed. DH thinks that water might have leaked after installing the valve to the pipe & before tightening it down. Then he added silicone caulk around valve & pipe. So, the water is trapped under the marble. With spectralock epoxy grout, there is no where for the water to escape or evaporate. I had 3 fans blowing on it all day yesterday with no change. Maybe a heat gun? I'm afraid the only way is going to be to try to remove the grout & try to dry it out that way. Any suggestions? Quick before I get my sledge hammer!

photo didn't attach before.

photo didn't attach before.

{{!gwi}}

Looks like a plumbing leak. An active one.

Latent moisture should transmiss back out through the the marble itself, assuming the marble was sealed with a vapor permeable sealer, which it should have been.

First place I'd look? The bar valve.

The bar valve, are you sure you got the correct fittings for it? If it's a european valve, the euro threadings can look similar to US threads. Euro threads will even mate to US threads, but they are cut slightly different so they won't give a good compression seal. That can give you a slow drip.

Aside from the source of your water problem (what does the shower wall back on? You likely need to open whatever drywall is in the adjacent room to access the plumbing) marble is very porous and moisture will escape right through it, as well as permeate it from the top.

When we installed our white marble floor, it all turned grey from the moisture in the thinset, and over the course of a couple days dried out to white again. You will always get dark water spots with marble which will dry out and lighten up.

But as others have said, it looks like there's some active water leaking and I'd be ripping drywall out from the opposite side of the wall. Drywall is cheap. Water damage isn't. Turn the water off to the shower.

I'm also surprised you used epoxy grout with marble - it's typically expressly suggested you don't, because of the porous nature of the marble. You often get permanent 'picture framing' where the outer edges of every tile darken permanently. Might not be such an issue with the darker grey and varied tones in the small mosaic.

I hope that you can remedy this issue without having to take it all down. It does look like a leak. Keep us posted, we can all learn from your issue and solution.

TorontoTim, OT, I worried too about picture framing on my light tile. But I have no issue with the Spectralock Silver Shadow with my whitish-gray tiles. The grout and the tile are nearly the same colors so that might have been a factor. On my sample board there is a very faint shadow around the tiles with the Spectralock Platinum that I tired. It would be noticeable, faintly, if I used that color. I kind of like the effect of the "blur" but not everyone would, I'm sure. My tiles are on a listello on dry walls, and not subject to water. I used Spectralock for the (long haul) cleaning ease. We live on a farm and the wall could be subject to a greasy paw (hand) or two.

I hope that it is not an active leak. The pipes were in the wall for at least a month & the tile was installed for quite a while before we installed the Hansgrohe shower system. The leak happened when we turned the water on - realized there was a slow leak & tightened everything. Unless something happened during the installation?? Right now I'm using heat to see if I can dry it out. If not, I heard about using a dehumidifier. I'll keep you posted.

Great.

The pipes were in for a month, but was the system pressurized during that time?

I think it's pretty clear from the majority of the comments that folks think you do, indeed, have an active leak.

I think it's pretty clear from the majority of the comments that folks think you do, indeed, have an active leak.

Water will not get trapped under the marble, unless you used a water based sealer, in which case, it would take longer to dry out, but it WOULD still dry out. My question is whether the pan membrane is sitting flat on the bottom of the shower, and the bottom of the cement board sitting right on the membrane, so that water is whicking up the wall. Let me ask you-- are you noticing anything that looks like the shower might be leaking in any adjoining area? Also, in the picture, it looks like the floor may be showing as damp directly under the marble. is that just my imagination or no?

That looks like a water leak behind the wall. Thinset drying out would be in random splotches not a long downhill pattern like that. It just wouldn't be that regular and it wouldn't be darker near the floor. Water spreads when it hits something and runs downhill, so that pattern is consistent with an active leak.

You said "the leak happened when we turned the water on..." Of course it did. If the water was shut off to those pipes and fittings, what would there have been to leak?

If I can tell that the wall is wetter near the floor, that's not just a little dampness that you can dry out with a fan or a hairdryer. The best advise here is to turn off the water if you haven't already and remove drywall on the opposite side of the wall. That is probably the only chance you have to save the tile if you still can. Bigger potential problem is that if you don't, the area is likely to stay wet enough long enough to create mold and mildew problems -- even rotting or draw termites. The longer that sits wet or gets wetter, the bigger the problem you will have in cleaning it up and fixing it. I hope we didn't hear from you today because you've been busy doing that. Good luck.

This post was edited by lascatx on Tue, Mar 19, 13 at 0:14

Whatever happened with this? I'd like an update as we have a similar problem on our marble shower floor (with no resolution yet).