Help solve MYSTERY? Marble tile shower floor always "wet" in some areas?

[chumbley]

I'm certainly no expert - but from my limited knowledge I don't think "pinholes in the grout letting water under the tiles" is your issue. Grout isn't waterproof anyway (and sealing it doesn't make it waterproof either).

Is it possible the membrane failed in these areas, allowing the mud bed to saturate?

[bbcamp]

Stacey, we still haven't heard from your installer exactly what method he employed in building your shower. I think that you have a combination of inadequate slope and blocked weepholes in the drain fitting. Correcting both of those problems would allow your shower to dry out. Unfortunantely, correcting both would also involve tearing out the shower floor.

I don't buy the thinner grout fix. Unless you used an epoxy grout like madam is suggesting, you will get water seeping through the grout. Also, your stone tiles may also be letting water through them. Both of these conditions are normal, not flaws in materials or workmanship. They are the reason we install sloped liners and drain fittings with weepholes in them. If there is a workmanship issue here, it is as I stated above.

[astrojeff]

OK, big disclaimer here that I don't have shower tiling experience, but I can't help from chiming in here. But "pinholes in the grout" causing water to leak below the tiles? Are they claiming that (sealed) grout is waterproof and that a properly installed shower tile job has no leakage through the grout? If that were the case, then wouldn't you have the classic "moisture sandwich" between your perfectly sealed tile surface and your perfectly sealed shower pan? And if that were the case, then certainly any pinholes would cause water to leak in but never evaporate out, potentially leaving hard-to-dry wet spots?

Seems to me that you want moisture exchange through the grout. Is that perhaps an inherent problem with stone that you need to seal it so thoroughly that any water that does inevitably seep in never can escape back out (except that beyond the saturation point which then leaves through the weepholes)? I'm just wondering. In any case, I'm skeptical of someone blaming wet spots in the shower base on holes in the grout. You will never be able to fully hermetically seal that grout and eliminate pinholes, and even if you could, I don't think you'd want to.

[staceyneil]

Madam, Thanks for the suggestion.

Unfortunately the grout lines in some places are SOOOOOOO tiny, I can't imagine how anyone could cut them out (but, what do I know? Maybe they can.) And they are probably the places that are the culprits, if seepage through voids in the grout is in fact the issue.

I just got off the phone with the tile manufacturer. They seem more than willing to help us diagnose the problem and come up with a solution. They're sending an installation questionaire for my installer. I hope, hope, hope they can come up with a good solution!

[staceyneil]

What you guys are saying makes perfect sense.

My installer is coming tomorrow to look at it.

[Houston Remodeler]

I had this problem once before. For some odd reason water was collecting in the thinset layer above the kerdi in a shower. We dug out a few grout lines to see what happened. Let it dry, and after one shower the grout lines were full again. Took a shop vac and sicked out the water, they refilled from the other water under the tiles.

We removed all the grout. Re-grouted with spectralock and no more problems.

BTW, Thanks Henry.

[Bill Vincent]

I've been staying out of this up till this point because I didn't want the fact that I was the installer to influence any opinions.

Slope is not the problem. There is literally 1" of preslope all the way around in a 3'x4' shower. On top of the preslope, I coated the preslope with Hydroment's Ultraset-- about an 1/8" layer on the base, and about 1/16" all the way around the walls up to about 12" off the floor. additionally, I really gooped up the floor- wall junction all the way around to make sure water didn't hold there, as well as strengthening that junction through thickness. I then screaded the final slope, and the rest of the walls were hit with 2 coats of 9235 up to the ceiling. This thing will not leak.

Now, if it were just around the drain, I could see the plugged weepholes, and in fact, that's what I thought it was at first. The problem is the other two areas. If they were all attached, or if the whole floor was staying wet, then the other two areas would make sense with reference to the clogged weepholes.

But just for the sake of argument, lets say the preslope is flat in those two areas. It would have to be flat enough to hold enough water to completely fill the pan so that water would rise to those to areas to keep them wet. That's why I say it would make sense if the whole pan were wet. This is why Stacey came in here to get other opinions, and why I stayed out of it to see if any of you could come up with something I hadn't thought of yet. I'll be going over there tomorrow, and let you know what I find.

[Lazarus]

Stacey~ Obviously sorry to see you have a problem. Having said that, I'm happy to see that Bill V. is your contractor. He is a professional and a "stand-up" guy. I know he'll work dilligently in your behalf to solve the issue.

[staceyneil]

Thank you, Laz, I'm also confident of that!

[Bill Vincent]

Well, we got a definitive answer today, but not from anything I did. I got to Stacey's house, and because I couldn't figure out why the fan hadn't been able to dry things up even a little over the last week, I tried sitting there with a blow drier, holding it not an inch from the stone for about 5-7 minutes. By the time I was done, the stone was pretty warm to the touch, but still hadn't changed color at all. I thought for sure if it was moisture, at the very least, the surface of the stone would've dried out, and then darkened back up afterward. But it never changed in the first place. I was starting to wonder if the stone hadn't been oil stained from something in the shower (shampoo, body wash, etc.). I even talked to someone at Artistic Tile (the manufacturer), who's convinced that there are two issues going-- one being plugged weepholes, and the other being "birdbaths" in the preslope at the edges where the stone is discolored.

No matter what, Stacey's husband put an end to all the controversy tonight. Why we didn't think of this beforehand, I don't know. He works at a boat yard up here, and has access to a moisture meter. It's not a stain in the stone. In spite of the whole thing with the hair drier, it IS wet. So I'm going to see about tearing up around the drain and redoing it. I still disagree with the "birdbath" theory, at the edge, though. It would seem to me that the birdbath would have to come to just shy of the surface in order for the Moisture to get that high? One way or the other, it's going to come apart, and we'll see for sure what's going on in there.

[Davestone]

I haven't kept up with this but "paint on rubber membrane" was said to have been used in the first post,was this a roll on Bill?I was thinking it was helping to keep things wet under the stone.Bummer,stone in showers can really be a problem.

[Bill Vincent]

Hi Dave-- It was Hydroment's Ultraset. It's a urethane "goop" that trowels on. Way too thick to roll on. I like using it for pans because it's both water and vapor proof, as well as being tough as nails once it's dry. That was used as the pan membrane under the mud. Not directly under the stone.

[JC]

Water around the drain is common with marble coz it usually dries out last. the other spots sure look to me like flat spots with the liner.

cant see weepholes clogging that fast.

You said you did another slope on top with mud.that one may be good but water would still lay on the liner if the pre-slope is flat. its gotta be...what else can it be?

Since you have mud directly under the marble..why not lift the tile and do another membrane on top of the mud..dont have to seal against the drain..in fact leave a little bit short for drainage...

or if you have the hieght then go over tile w/membrane

then do the spectra lock..it seals and brings out the colors in marble nicely.

Stacey, mold wont grow in cement..it needs food and doesnt like lime...relax

The only other thing I can think of is if the sealer was puddled really badly and soaked throught the grout in those spots..would take alot of sealer and it would prolly have to be solvent based to penetrate that deep..long shot

Let us know what you find.

[Bill Vincent]

Jim, there's atleast a solid inch of pitch in 2 feet in that preslope. No chance that it's flat. Additionally, when I do the membrane, I'll goop the wall/ floor junction hard to give it an extra little bit of slope and to make sure the membrane is good and strong at that junction. Either way, I'll find out for sure soon enough when I take it back apart. I'm not going to remove the whole thing-- just enough around the drain to unclog the weepholes and about 7" back from the walls at those two spots to make sure the preslope is as I say it is. IF you're right and it's not, it'll get fixed, as well.

[ob1kanobee]

I'll stick with my original post #8.
-clogged weep holes
-holding water under tiles on top of the water proofing. (might have been mitigated with more shower slope but I doubt it).

Seen this many of times by the best of us.

Regardless I am confident Bill can rectify it. He has forgot more than some pros know.