Clogged weep holes, “traditional” vinyl liner, and a saturated mud bed. And, it’s porous marble. Which is just s hard sponge that you’re glueing to your walls. You have to have the right mindset to accept water stains as part of living with porous stone.

Sealers help protect the stone, they don't make the stone water proof or stain proof.

What you're seeing is moisture that is trapped between the tile and pan liner, escaping through the stone. You can seal the stone (and grout with a stone sealer). Sealers allow gasses (as air) to pass through them and will not hinder the evaporation of moisture.

If a mud bed was installed over the pan then it could take longer for it to dry properly.

It is normal to see stone like this in a wet area such as a shower floor.

To get to the weep holes, the entire shower gets demolished. Maybe some other tile pro will come along with advice on how to handle this with your contractor.

Well, marble is very porous and also very susceptible to staining, discoloration, and etching. Some people love this “living finish” aspect of marble, but if you are not someone who does, it is a really poor material choice. Even sealing won’t prevent the marble from looking lived with over time (on that note did you seal it or did you pay builder to do it? As in are you sure they did it, as it seems at least where I am builders generally expect homeowner to seal natural stone and grout and so on after possession, they won’t generally do it as a default).

Now, whether your shower is draining properly or not, can’t say from photos or discoloration alone.

Unfortunately, this has been a problem for others who posted on houzz before.

Here's 2 links out of many

[https://www.houzz.com/discussions/permanent-wet-look-in-white-marble-mosaic-not-good-dsvw-vd~3142099[(https://www.houzz.com/discussions/permanent-wet-look-in-white-marble-mosaic-not-good-dsvw-vd~3142099)

[https://www.houzz.com/discussions/carrara-hex-tiles-on-shower-floor-wont-dry-out-dsvw-vd~3124883[(https://www.houzz.com/discussions/carrara-hex-tiles-on-shower-floor-wont-dry-out-dsvw-vd~3124883)

Without knowing the actual construction. I would guess no preslope as required by IPC. Don't mention this at first. Ask the contractor to describe steps to waterproof base. If liner or pan was laid flat on plywood your case has been made for a complete redo. I would say you have a 80% chance from what I see in the field.

https://www.ceramictilefoundation.org/blog/everything-must-slope-to-the-drain

Not my words. I copied to save typing.

Each shower detail in the 2018 edition of the TCNA Handbook that uses a clamping ring drain, requires sloped fill (pre-slope) under the shower pan membrane.

You are correct that many times this is not provided by the plumber; however, it is part of the installation requirements which makes sense. In order to get the water in the system to the drain and evacuated, it must slope downhill. While it may not leak when installed flat on the subfloor (without pre-slope), this trapped and stagnant water will eventually emit an odor that is offensive.

Additionally, if the tile installer encounters a shower completed by the plumber that does not have a pre-slope, it is the responsibility of the installer to provide it. While this is not fair to the tile installer, completing the shower without it is also wrong, it must be there.

Informing the builder (in writing) of the plumber’s error would do two things.

• The builder is now responsible to force the plumber to install the pre-slope per the requirement or pay the tile installer to do it.
• Beyond that, it is the responsibility of the plumbing code enforcement officer to ensure that the pre-slope is part of the shower assembly.

The bottom line is that the pre-slope must be there, so someone has to do it.

Oh dear. That's a pretty definite line of "wet" stone vs "dry" stone in your shower. And 8 days is a LONG time to have water still showing up underneath a tile.

Sigh. The "good news" (if you can call it that) is the porosity of the marble is ALLOWING YOU to SEE the problem without having to wait a few years before something BIG happens (like the basement ceiling falling down due to severe water damage). With porcelain tile, you never would have known about the problem until it was years too late to do anything about it (ie. get the builder/contractor in to fix their mistake on their dime).

Once you get this dealt with and the redo is scheduled, I HIGHLY recommend you go with PORCELAIN. You won't have the maintenance nor the other issues with marble.

And when the redo occurs, PLEASE be there on a daily basis to take pics so that you can document EVERYTHING while the work is being done. If these guys missed the slope then I question what else they missed - moisture barrier anyone?

thanks for all the input. I'm thinking they may think that there was not grouted properly as when I told them about it, they sent one of their guys over and they placed more grout around the drain. Prior to that, there was small strands of blue plastic barrier? showing through? I'm going to give it another two weeks and if there are no changes, the tiles will have to be removed and everything reinstalled.

Strands of a blue plastic barrier? I hope not, they may not have installed the pan liner properly.

Grout on the wet floor needs to breath properly, I wouldn't recommend using an upgraded grout that does not allow moisture to penetrate. If the grout is able to breathe, moisture is able to escape.

Some moisture will escape into the pan (under the tile) when it drains, this is normal. If an upgraded grout is used, moisture is unable to escape, it will continue to collect in the pan and will eventually force its way out. This will cause more problems and headaches down the road.

If you decide to replace with porcelain tiles....no upgraded grout!!

Minpho, the grout they added does nothing. Grout is not waterproof. It is like a placeholder between the tiles that directs the water downhill to the drain and then when it does let small amounts of water through (because it is porous), it also allows that same water right back out again as it dries (because it is porous). Grout has worked fine for centuries despite this if the shower is built correctly underneath the tile.

A properly sloped and waterproofed shower floor never looks like yours did after 8 days of drying out. Even with marble ("hard sponges") and grout (which lets water in and back out), your shower floor has an obvious problem. You can see what it is. The wet area is not sloping enough toward the drain to dry out, or it is not built on a waterproof bed - and the soggy bed underneath it is full of stagnant water that is keeping your tile wet. Or both.

Your builder is responsible to give you a waterproof shower that does not leak, does not pool water underneath the tile, and dries out after showers. There are things that can help you in this situation, but you must act now to handle this correctly. Listen to the people here who have "PRO" under their pictures. Most of them have great advice - especially anyone having to do with tile. You may also have help available from your building inspector. Was your shower inspected as it was being built? Does your town do that? Did they okay the pre-slope and the waterproofing method?

Go read the things that Creative Tile Eastern CT linked you to read. Ask more questions if it does not make sense to you. You MUST at this point make yourself understand how a shower is supposed to be built because you are now in negotiations with a builder who is not going to want to tear the whole thing out and redo it. Re-read what Creative Tile told you. He is telling you how to talk to your builder about this, what to ask about how the shower was built. You first have to read up on showers and understand terms like "pre-slope," "waterproofing," "shower pan membrane," and "clamping drain." Because otherwise, you can't discuss this and negotiate with your builder. That is why sometimes having the building inspector on your side about whether the shower was inspected during its construction (or not) is good. But if your building inspectors don't do that with new houses, then they are useless to you. Calling the town building department and asking if the inspectors do inspection on showers to ensure they are sloped and waterproofed properly before they are tiled in new home construction will tell you whether the building department will be any help to you. If they are supposed to do the inspection and your builder did not have it done, then the building inspector may come look at your shower and tell the builder to fix it.

Building inspectors look for code compliance, not quality.

Here are a couple of YouTube videos that show showers being built. The first is a quick overview of all of the steps. The second I included because it shows how the contractor puts a pile of pebbles around the clamping drain so that when he builds the mud bed for the shower, he does not clog the holes in the drain. Those holes are there so that if water does get through the grout and tile, it can go through the mud bed and the slope of the shower will make that water flow to the drain, where there are holes in the clamping drain that lead the water to go down the drain, instead of sitting between the waterproof bottom of the shower pan and the tile, stewing in the mud bed and breeding stinky bacteria and mold. People here are saying that your holes in the clamping drain are plugged up, so the water is sitting there, under your tile.

and the one showing the pebbles:

In this video, he does more explaining. Like, "the pre-slope is before you put the liner in, so that any water that gets into the liner gets directed to the drain, and the reason for that is that this drain has weep holes in it." He goes on to show how the drain has weep holes with runnels leading to the holes, so that any water that gets to the drain will have a place to escape, and go down the drain. He shows that he will build a mud pre-slope, then put the waterproof liner to the drain, then put the clamp on top of that liner, clamping the liner in place on the drain body. He says that then he builds another mud bed on top of the liner. This starts at 2:30. You can watch him build the whole bathroom, if you want. These were the important points for your shower.

Joe, that is what I am wondering. Did it get inspected and pass? Was it supposed to be inspected and it wasn't? Wouldn't the code enforcement officer be of help in the event of the second instance?

Hello,

Bellow is the link to my recent article that summarizes the research we have done on the subject of marble moisture discoloration on shower floors:

https://www.houzz.com/discussions/5956434/marble-moisture-discoloration-don-t-blame-the-stone

@ Star Tile. - Great link. Thanks

For those who are interested, see bellow the link to my article on how to properly install marble shower pans with the traditional water-in, water-out method including the limitations it has for resin-backed stone, impregnating sealers and why.

https://www.houzz.com/discussions/5956524/carrara-marble-and-water-in-water-out-shower-pan-method