If there is no sign of a water leak outside the shower than it is not a waterproofing problem.

What the photo is showing is an absorptive material , like stone -- ie.marble mosaic .

Was the spot -- large wet area -- on the floor when you bought the house ?

If sealer was not applied on the shower floor and now it is , you can conclude that water is trapped in the stone and more of it is contained -- hard to say what depth without knowing the construction procedure -- in the large wet looking area . The sealer will and is retarding the humidity to escape .

The tile is not stone. The tile in the darker area is the same color as the tile elsewhere. It is the grout that is darker.

As as far as water outside the shower, well, I can't see underneath the shower floor.

I had a similar problem with dark grout. It turned out that even though the preslope was correct my mosaic tile with a bit of lippage was damming water from flowing properly to the drain and the grout never fully dried. It was a floor only issue but the problem was that fixing the floor only would compromise my entire Kerdi waterproofing so it turned into a total shower tile tear out and redo. One option was to do the floor and first row of wall tile over but my contractor and many pros here advised against that solution for it would be merely a patch not a perfect new shower like I had paid for.

It was redone last month and the grout is perfectly consistent now and dry within an hour.

Good luck.

Ah, interesting. That seems like a possibility as I have noticed lippage with my bare feet when I stand in the shower. Thank you!

crl,

from the photo supplied , is clear that your mosaic tile is darker along with the grout .

If the tile is not stone , sorry , I can't help .

I didn't see such a mosaic to be affected if it is ceramic or porcelain -- darkening effect -- , unless it is stained on the surface by a contaminant . However you are concerned with the growing of the stain , if I understood you , right ?

I can only add to , so eloquently presented by Tundra Finish Works , that having a soft glazed ceramic it should not be used for floors . Just assuming was not used in this case . Without precisely knowing the type of materials and processes used , hard to pin point the real problem , but sounds potentially right what TFW said .

@roarah,

I would be really interested in the details of the logic behind this

'' I had a similar problem with dark grout. It turned out that even though
the preslope was correct my mosaic tile with a bit of lippage was
damming water from flowing properly to the drain and the grout never
fully dried. It was a floor only issue but the problem was that fixing
the floor only would compromise my entire Kerdi waterproofing '' where Kerdi was used and the grout stayed wet due to minor lippage in the mosaic tiled floor .

How long it took in the prior -- the quoted option -- set up , for the grout to dry vs. your new configuration .

Coincidentally, you posted while the builder's foreman was here doing a warranty repair on another (minor) issue.

I asked him to take a look. He agrees with me that the tiles are definitely not stone.

He was quite sure (of course) that there was no waterproofing issue. He says the shower has a water tight system. I did not press as to what kind, though I really should have. He agrees that it is water causing the discoloration

His suggestion was to start by allowing the entire shower to dry out for a few days and see whether the discoloration disappears.

He was quite certain (of course) that it is just a cosmetic issue.

The master bathroom is on the second floor. I cannot currently see any water damage to the ceiling below.

I can see about getting the city inspection report. And I can try asking neighbors as well--the whole subdivision has been built by the same company though they may well have had multiple tilers, but I barely know anyone yet as we just moved in.

Is it worth getting a tile inspector involved?

I feel that the contractor/foreman was dismissing your concerns when he stated that it was "just a cosmetic issue". If cosmetics weren't part of the initial design plan, what was? If cosmetics weren't part of the plan then they could have just installed a fiberglass standing shower stall. Absolutely what the install looks like should be part of what you just bought. They need to fix this.

I might not understand your question euro, but my previous floor held water for more than 24 hours. I could actually wipe water out of my grout lines more than a day after a shower and even when it became dry to the touch the grout stayed dark after that for more than a week.

There were two theories to why. The preslope and flood test were deemed acceptable by a kerdi rep who came to help me trouble shoot the issue, so it was suspected that the tile was damming the water or that water was getting behind the wall tile between the Kerdi membrane and dripping into the floor from behind. To properly fix either issue without compromising my waterproofing was to tear out everything. When they ripped off the wall tile right after we soaked it thoroughly using both shower heads and four jets no water was behind the tiles on the Kerdi membrane so it seemed the lippage within the floor tile was the culprit.

my new shower floor is bone dry within an hour or two now...

I agree that the foreman was trying to deflect. I could try putting in an actual warranty claim and he might bring a tile guy with him and I might get better answers or a better result. I will say on his behalf that he said that in response to my questioning whether there might be a waterproofing issue so in context he was saying I didn't need to worry about leaks. (Which is not to say he's right about that or that cosmetic issues aren't important).

I'm not a hundred percent sure how to proceed at this point though I do really appreciate the guidance I have gotten here. I think there are a few options. One is to file a warranty claim on Monday. Another is to wait for the shower to dry out completely to try to gather more data as described above. Yet another is to try to contact a tile inspector on Monday.

One advantage to filing an actual warranty claim is that I might be able to get more information from whoever shows up about how the shower was built. That might be useful information for a tile inspector or other third party if one becomes necessary.

Hmm, maybe let the shower dry out. Then if the dark spot repeats, file a warranty claim. Then proceed from there. . . .

@roarah,

I don't know why the preslope is used with Kerdi in the same sentence .... since the Kerdi is a topical membrane . And the theory about the '' mini dam '' or the '' lippage '' doesn't hold , but I am glad that you are happy with your new shower :)

Bone dry in an hour or two is quite impressive , but very few materials used for a shower construction could have those properties . Glad to hear you have them in your shower .

@crl ,

I do wish that aesthetics will be covered by your warranty claim , but doubtful .

The thing is , the argument could be made that by introducing the sealer in your configuration -- shower floor -- , the evaporation process is slowed down by a very high % , thus the wet looking patch(es) .Try to make it work with your builder and , ask them what is , in their view , a decent amount of time -- precise # of days -- to allow the shower floor to dry , before you start looking in '' wrong doings '' of its construction .

You can also ask them to share with you the process of building the shower and give you samples of the tiles used .

I'm not a hundred percent sure how to proceed at this point

I agree w/Roberto Eurocerob and enduring/Roarah made some great points.. You have a year, you have a builder that is communicating well and you also have a lot of $ and likely w/that stress tied into a major purchase. It is easy to worry about the worst case scenario and that is what i pointed out likely not making you feel warm and fuzzy inside!.

While i stand by my assessment above i would also question youre sealer (type/application materials/method and condition at time of install and cleaning, and remind you..... you now are the last person to work on the shower floor in question by sealing it yourself and that works in the builders defense if they choose to use that).

You could have a little lippage issue and a sealer that enhanced that area. again were just guessing at one single picture with scant details.

Regardless you now have a bunch of options to consider as well as you now know way more than the average homeowner will ever care to learn about tile showers..Knowledge is power- best

I will add I do squeegee walls and quickly the floor too to aid in drying. I did this with the orginal shower floor too. The grout might not be bone dry but no more bird baths or even water drips anywhere. And again my GC, tiler and a Kerdi rep were taking guesses as to what the issue was and since it was a do over it could have been a wall or floor issue since they ended up redoing both. They did not change a preslope though. I have a Kerdi shower base I believe and than I have Kerdi membrane on my walls. I am no pro and maybe I have the terms wrong, sorry.

i will add to the cosmetic concern, at one point when we were assured that the waterproofing was keeping water from doing structural damage to my walls and frame work I mentioned that if it was only cosmetic I than could maybe live with it. I just dreaded the idea of more construction at that point. My G C said absolutely not, it was not a leak concern but it is a mold issue he pointed out which is indeed not cosmetic if it is darkening do to poor drainage.

Well, since they told me they didn't seal any of the grout in the house and sealing grout (except for the epoxies and newer not quite epoxy grouts) is commonly recommended, I will be quite pissed if that's somehow used to say it is my fault.

UPDATE

So the builder's tile guy is here and tells me that the tile is stone of some kind. So I was wrong about that.

He is telling me that the dark spot (which is still there even though we haven't taken a shower in there for over two weeks) is water being held. He is insisting that this is normal because there is a "sand" layer that holds the water. And that it will never dry out, but that isn't a concern of any kind and won't cause mold.

His plan is to flood the shower and leave it flooded for a few hours, then come back and drain it and seal the whole thing. I agreed to let him proceed with this plan.

His description of the shower construction is a layer of mud (I think?) followed by a water proofing layer (apparently not kerdi) and then "sand" and then tiles. He tells me the water proofing layer goes up six inches on the walls and the rest of the walls are waterproof because they are cement board.

This sounds wrong to me. I know our GC on our remodels in our previous house used kerdi up to above the shower fixture for waterproofing. It was my understanding that that was the correct way to do it. Is cement board acceptable practice?

Thanks!

It is often the Case that cement board is used over poly on walls but not with a top waterproof coat. If you have a moisture barrier between the CBU and wall joists the walls are ok. If not I would tear out the whole stall. I do not know about your floor construction but it seems like a molding bed of yuck to me if it never fully dries.... Good luck.

Thanks crl for the update . It seems that what you have is a traditional shower where the liner is behind the mud floor -- sloped to the drain -- and then the mosaic . I would recommend against flooding procedure which will further get the moisture -- water -- in . Don't get me wrong , I am curious by nature and be glad to know the outcome , but it will further accentuate the problem and further sealing will be useless .

There are many disadvantages to a traditional waterproofing ( pvc or similar liner ) vs. modern waterproofing ( surface membrane ) including the efficient release of humidity accumulation . If you have a traditional shower , it will be '' impossible '' to have the aesthetically -- back to complete dry state -- dark areas removed without a redo .

As a last resort , I would try a sealer remover to try to open the pores so the mosaic and the cementitious grout could breath , but no guaranties on the final outcome . And this , depends of the construction of the shower , where the cement board is '' not interfering '' with the mud bed and act as a conduit for humidity -- in excess of normal absorption through grout -- from a saturation -- weep holes blocked -- point of view .

Thank you. The flooding and sealing has happened. The tile guy said we could use the shower again starting tonight. His goal was to make the whole shower floor even, which means darker than when we purchased. I'm okay with that as long as it isn't a problem from a water/flood/mold perspective and as long as it works without substantial ongoing maintenance. I asked if I needed to reseal and he said yes, but didn't commit to how often.

Assuming I am satisfied with the looks aspect, is there reason to be concerned about mold or premature failure of the shower in some way?

I am also not sure how to clean this shower floor now. I would never in a million years have chosen marble for a shower floor, ugh.

I really do appreciate the help on this. It's a little frustrating occasionally to have a brand new house where I didn't get to specify everything.

Well, I would say let's wait and see how it progresses -- give it few days -- . It shouldn't take long for signs -- random wet patches , efflorescence -- , if it doesn't work .

So here's what it looks like about 8 hours after the tile guy applied sealer.

(Haven't turned the water on at all.)

His plan is to flood the shower and leave it flooded for a few hours,
then come back and drain it and seal the whole thing. I agreed to let
him proceed with this plan.

Crl this plan is partially futile if the Tile isnt first dry and there are "no" wet spots evident at time of flood....(Did you use a dehumidifyer ? even in a very wet mud pan it will dry out the low spots or bird baths in a weeks time)

If we have a dry consistant surface to start the test from we can only then see the results we need to determine the cause as it dries out and as to Roberto Eurocerob's very skilled advice I agree its a bad time now to flood but this is our only option to troubleshoot definitavely at this point and a one time flood or two cant hurt sand, portland, grout and the proper thinsets now so dont worry about it........ Secondly sealing any wet or moist installation is not advisable ever. It needs be bone dry and cured out. Especially with stone and a non vapor permeable type sealer = a bad idea.

SIDENOTE AND MORE CONCERN? How can you just now be told you have stone??

His description of the shower construction is a layer of mud (I
think?) followed by a water proofing layer (apparently not kerdi) and
then "sand" and then tiles. He tells me the water proofing layer goes up
six inches on the walls and the rest of the walls are waterproof
because they are cement board.

As i suspected and lets hope there is a proper shingle lapped moisture barrier that laps over pan liner or it is another rule for tearout ......

it needs be torn out and replaced to answer youre concern of future issues or start again with the dehumidifier... Still im betting a preslope and drainage issue and if so it would promote future mildew, stagnant water buildup and eventually mold and maybe efflorecence... In time.

To clarify my test advice:

The flood test I advised earlier is only applicable when it dries completely and SPOT FREE first. Im afraid now youve further confused the chance of an answer as to future mold/mildew issues or leak ( which should have been ruled out with a late stage flood test... To answer again youre question? only time can tell.

Im gonna irritate you here but are you sure it ever was initially dry and NON wet looking in the dark spots and can you prove that? is there a simple chance you used an enhacibg sealer when you sealed it youreself?

If its not water pooling below? if its not an actual mismatched or non color dye/matched tile? its got to be a sealer mix up.

Try and dehumidfy it again or get to tearing it out and when you do tear it out specifically look at the affected areas for proper preslope /drainage.

sorry for your troubles im sure its confusing and a trying time- best

Sorry I missed this thread the first time around.

Looks like you got good advice.

Mud beds usually do stay somewhat damp once used. Clogged weep holes can exacerbate the held moisture.

Natural stone tiles or soft body (absorbent) ceramics can act as indicators for and show the held moisture more than a porcelain tile.

Sealers can do strange things to mud showers, especially if it percolates down into the mud bed.

I do have to say that I think you're getting somewhat suspect advice from your builder. I'd like a GC to now the difference between "sand" and "mud". And why wet the floor then seal when wet? Tundra is correct, sealers should be applied to dry surfaces.

Thanks to both of you!

I am not all that confident in the builder's people on this either. I suspected all along that there might be a problem with the underlying build of the shower.

But I don't really see how I can proceed without letting them try to solve the problem. I'm definitely not an expert at all so I can ask questions all I want, but I don't really have much basis for insisting that they can't try their remedies.

They assured me that they have had this problem with white marble showers and their solution fixed the problem. Their explanation was that flooding the floor would even out the color and then the sealer would lock that in. I was doubtful, but again, I felt that I needed to let them try.

I guess I could just pay out of pocket for the whole thing to be torn out and replaced, but since we have a warranty, that doesn't make a lot of sense to me. As long as they are actively trying to solve the problem, I think I need to try to work with them so I don't void the warranty.

At this point I have emailed and left a phone message saying that their fix didn't work. I feel like I need to wait to hear what their next proposed solution is.

I do continue to think that at some point, I might be well served by hiring a consultant to advise on the proper solution. (I trust you guys, but it's not a very effective argument that some people on the internet told me X or y or z.). And depending on what they propose next, that point might be sooner rather than later. Any suggestions for finding such a person? I'm in a small city in the mountain west.

(I'm going to measure the shower and if a cast iron base fits and they agree to replacement, maybe I can convince them to go with that instead of tile. Not so sure I love the idea of giving their tiles guys a second shot at this. If replacement is the solution and I must go with tile, I'm choosing porcelain even if I have to pay for the tile out of pocket and I'm taking pictures every step of the way.)

'' Their explanation was that flooding the floor would even out the color
and then the sealer would lock that in. I was doubtful, but again, I
felt that I needed to let them try. ''

This really doesn't hold ................. where water molecules will occupy all the available pores , '' empty '' spaces during flooding process , then you '' seal '' them in place ? It is not doubtful , but Impossible . There is no known sealer -- among other things -- which traps and seal water molecules in an inert state , where they just sit there and wait to accommodate -- aesthetically needed -- the situation .

'' I do continue to think that at some point, I might be well served by
hiring a consultant to advise on the proper solution. (I trust you
guys, but it's not a very effective argument that some people on the
internet told me X or y or z.).''

What it is important to know is the arguments you need to know in dealing with a willing contractor to remedy the situation . If unwillingness is in play , than a consultant is more appropriate .

I would still let the contractor -- he is cooperating -- try to remedy the situation . Maybe , he didn't know how the material will react , he didn't know how a proper traditional shower has to be build , he didn't now there are more options in using a surface membrane , sealing the stones before and after grouting , etc. ........ lots of unknowns , but if he is willing to make it right , work with him .

To eliminate -- aesthetically -- the spotting , the redo of the shower floor is needed . You can either try to use it for 2 or 3 months -- have a written extension of the warranty from the builder for your shower -- and see what happens or ask for a redo , but limited to standards and recommendations in place at this time -- TCNA recommendations are a good start -- .

Thank you! I haven't heard back from the builder's people. I am not happy with the current state of the shower floor. Partly because of looks and partly because I'm concerned that there's birdbaths or clogged weep holes and that sounds like potentially worse things than a blotchy floor down the road.

I guess I will wait and see what they propose next. I'm guessing they won't get back to me until next Tuesday given the holiday weekend.

(Getting really frustrated not to have access to my shower--we choose a brand new house with two full bathrooms to avoid having to share with the kids! But I don't want to confuse the situation by using it.)

I appreciate the help!

I'll just write a little more. Probably a lot more...

You have a mud bed with a vinyl liner. From the subfloor upwards it should consist of a deck mud preslope, covered with a vinyl membrane, covered with a second layer of deck mud, and that second layer is covered with tile. Something like this:

Weep holes, some at the clamp, some in the bolt holes, some at the throat threading:

And here's how the weep holes relate to the membrane:

Some installers take a short cut and insatll the vinyl membrane flat on the subfloor. If they do that, the mud bed can hold moisture as there's no slope to encourage it to get to the weep holes and go down the drain.

Some protect the weep holes with a manufactured weep hole protector, or they'll use a handful of tile spacers or a handful of gravel around the drain. It simply creates a bit of open space so water can more easily flow through the weep holes:

If the weep holes are left unprotected, the mud packed tight to the weep holes can make it difficult for moisture to pass through the weep holes. I've even seen installer who don't really know what the weep hole channels are for and they run a bead of sealant around them, rendering them ineffective.

The leaner the deck mud mix, the more easily water can percolate through it. A 5:1 sand-cement mud will drain better than a 3:1 mix for example.

If the weep holes are clogged, the floor area around the drain can appear dark due to held moisture. To remedy, the tile around the drain can be removed, the deck mud broken out, the weep holes cleared, protected, then everything patched up. Here's an old thread where Bill did that.

Try to wrap your head around what your builder is saying. He's pretty much saying that because your floor is draining unevenly and that parts of it show wet and parts of it show dry, that we're going to flood it to get it all good and wet and saturated, then we're going to try to seal that moisture in so that the entire floor will always look wet.

Hopefully that logic is one of those things that make you go "hmmmmm...".

Thanks mongo! That does help me understand how the shower is built.

My problem is convincing the builder's guys that there is a problem with the way the shower is built. I've tried to question that and they aren't having it. Since they admit having this problem with other showers, they may really not know how a shower should be built. Or they may not want to admit that they should be spending the money on fixing them, including mine.

Can I ask another question? What would be your ideal solution at this point? If this were your shower, what would you do?

And if we end up with them tearing up the entire shower floor, does that cause any problems with the shower walls or bench?

The dark inch up your grout line on your wall by the floor indicates that water seems to be seeping up your wall grout. I think you have a slope issue and the water that can not egress to the drain is being wicked up you walls. It is more than cosmetic.

I mentioned up thread that my GC pushed to have a total redo for a floor only issue due to the possibility of compromising my Kerdi membrane on the walls. However a Kerdi rep said he has seen it done where only the first few feet of wall tile are removed with the floor and redone. My GC agreed with me that I paid for a brand new shower and that is what I deserved and pushed the tiler to do it right not a patch job. That is also what you paid for do not settle!

Can I ask another question? What would be your ideal solution at this point? If this were your shower, what would you do?

There are so many variables, the best I can do is toss out a few generalities:

The recent flooding and sealing of the shower makes troubleshooting a little difficult. Had continued use of your shower resulted in a repeated ring of moisture around the drain, I'd assume the weep holes were clogged. If you wanted that repaired you'd have to break out a roughly 6" ring of tile around the drain, dig out the mud and clear the weep holes, then patch.

If the damp ring around the drain propagated into a good portion of or the entire floor being damp, then I'd venture that there was no preslope under the membrane and that the membrane was installed flat on the subfloor. That can sometimes be confirmed by going through the back side of a shower wall. Repairing that would require the entire floor to be rebuilt.

And if we end up with them tearing up the entire shower floor, does that cause any problems with the shower walls or bench?

It can go in phases.

Best case, the membrane is properly sloped. But the deck mud on top of the membrane has a few bird baths, or flattens out at the walls so the floor does not drain well. In that case, the tile can be removed and the mud re-sloped. The walls don't need to be touched.

If the slope of the membrane itself is wonky or nonexistent, to rebuild the preslope under the membrane would require the membrane itself being removed. Because the membrane turns up the walls, removing and reinstalling a membrane requires the bottom couple courses of wall tile to be removed so the membrane can be properly accessed.

I don't know how the bench was waterproofed so I really can't comment on that.

There are ways to rebuild a shower floor with a surface applied membrane, but I can't get into that here as it's a case-by-case basis.

Apparently you don't have any leaks in your shower, which is a good thing. It's more of a drainage issue. Drainage issues are not the end of the world, but they are disappointing in new construction when you're expecting a properly performing house.

Keep an eye on the shower and bench. Report issues to your builder in writing for warranty purposes. Your builder needs to understand that just because these drainage issues are typical occurrences in the houses he builds, it does not make them "normal" and therefore acceptable issues. He needs to reassess how his showers are built and simply do a better job at building.

The tile guy said the waterproofing layer--which I take to mean the vinyl--goes six inches up on the walls except with the bench it goes up all the way up the bench.

The original dark area was around the drain with the spot going further to the left. But by the time the foreman came the first time it had "spread" all the way to the left wall under the shower head. So based on the help here I would guess that the weep holes are likely clogged and there is probably an issue with the slope near the wall to the left.

Thank you! I really appreciate all the time and effort everyone has put into trouble shooting this for me!

UPDATE

The builder's foreman called me yesterday. He said that if the sealing hadn't worked there really wasn't anything else they could do.

I said, let me tell you what I think is wrong with that shower. When I said I thought the weep holes were clogged, he didn't know what weep holes were. So he said he would call the tile company and get back to me.

He called me back and said the owner of the tile company would be calling me and I would be dealing with that person from now on.

So the owner of the tile company called. He explained how the shower is built and what weep holes are designed to do. (Just like I had already explained to the foreman--oh the irony). Then he insisted that there is no problem with the construction of the shower. That the problem is solely with the stone tiles.

He promises that they will do whatever they need to to make me happy with the shower, even if that means replacing the tiles. He is going to call the rep from the company that sold them the tiles and bring that person to a meeting at my house early next week.

He insists that we should use the shower. I have been reluctant to do that because I am concerned it will make it harder to figure out what is actually wrong. Thoughts?

In person, I will again make the argument that the weep holes are clogged (and that there is likely a flat spot in the pre slope). If they continue to insist that is not the case, but offer to replace the tiles, should I accept that offer? Will pulling the tiles up reveal clogged weep holes if there are in fact clogged weep holes?

And, any suggestions on a replacement tile? I'm thinking porcelain? Any criteria I should be looking for to get decent quality? (The shower is small so we would be willing to pay for the tile itself if necessary to get durability and ease of care.)

thank you!

UPDATE

The owner of the company that did the work and the representative from the tile store came today.

They continue to insist that the problem is the tile, not the shower build. The owner of the company that did the work insists that if there was a problem with the weep holes there would be mineral deposits "growing" in the drain.

Their solution is to tile over the existing tile. I can choose the material. They agree porcelain would be a good choice.

This does not sound like a good solution to me. I am not convinced that there is not a problem with the shower build. And I am not convinced that tiling over existing tile even if there isn't a problem is a good idea.

I think at this point I should try to get a third party to come and look and advise on what should be done.

Thoughts? If you agree, how do I find someone knowledgable and with credibility to inspect?

Tiling over my floor was suggested, by the Kerdi rep at one point. I, after advice here and from my GC, said no. My main concern was that my floor was already not draining properly and what if water seeped through the wall tile and got into the orginal floor how would this water ever have an egress with a new drain and floor above it? I said no to that solution but it does not mean it is not an ok option it just went against how I was told a well built shower should be constructed, with walls first and floor tiled over wall so that if or when water got behind the wall it could still find its way to the floor and thus drain. It is a patch job at best and a breeding ground for mold at worst....

Thanks. I feel like they just want to cover the problem up so the shower lasts until the warranty is up.

Thanks!