Low spots in the mud base (bird bath). It looks like marble in your photo. That would explain the discoloring. The repair is to rip out and completely redo the base . Can this be done without compromising the water proofing remains to be seen. Any in progress photos would help.

Thanks very much. Yes, it is marble. The corners where the discoloration is are higher than the middle where the drain is. By low spots do you mean the underneath layer is uneven and allows water to pool? Sorry for my ignorance on these matters. I just don't know.

Could be a liner was not presloped prior to mud bed. Water would pool in the liner instead of flowing to the weep holes at the drain. Either way there is a issue. Inquire as to what method / steps were followed for waterproofing.

I had a similar problem with porcelain tiles. I hated the idea of a total redo after finally being finished with the addition but it was our only feasible solution any thing other than redoing my shower would have been a patch fix at a full price cost. I did have the orginal tiler redo the work for in my state I had to let him try to make good on the issue before I could get money back from him. I had kerdi walls which would be compromised so my fix was a total tear out and redo from floor to ceiling. The tiler got it right second time around ;)

It was inconvenient but very worth it now that my shower dries fully without discoloration of grout within hours not weeks. Call your contractor for a new shower is covered to function properly in most states. Your's is not functioning and can become a mold issue or cause structural damage else where within time. Good luck and I am sorry for you situation but it can be made right!

here is a closeup of a failed preslope done by one of our Local stone supplier/competitors sub contractor. I recently tore out.. The red material is the pan liner that sits on top of a bad "preslope" , notice the back corner how it dips down ?

when the tile and then the mud bed gets saturated from use it has no way to push water toward the drains weep holes or it pools in the low spot and never dries.

This same thing can happen with modern surface applied membranes but they will dry out quicker and we dont yet know how yours is built. As such if it can be repaired properly w/o tear out of the whole shower. By the looks of your drain grate its either a schluter/prova ...

As Creative tile stated we call these low spots bird baths and they can be avoided by verifying that the "shower pan flood test" drains out completely before tiling.

Roarah is a great example of a homeowner that caught this very issue and had her shower rectified properly right here on these forums....

The builder is telling me it isn't a mud system and described something like the membrane system. Any thoughts on whether that makes any easier fix? Builder not inclined to try. Thanks.

OK so you have A topical membrane, this means the waterproofing membrane is Just under the tile.

Under the membrane could be either A Mud screeded preslope or A prefab foam pan. Based on the pics youve got low lying spots around the perimiter in either the mud screed or the foam pan ( some of the lower density foam pans love to make bird baths when the installers step on them in the tiling process and indent them.)

Unfortunately Fully bonded membrane showers are the ones less likely to survive A partial repair in the removal process and the re-installation of the required membrane lap joints.. It is not advised to accept a repair if it voids any long term system wrrty.

The best advice I can give you is find out if it is a schluter membrane shower system or Prova and contact that MFG and request a 3rd private party Field rep does a site visit to advise you further. Mybe contact Roarah and ask her how she handled things and found resolve.

As a troubleshotting excersise id stop using the shower and see how long it takes to fully dry out.

Did you get a shower pan Inspection and was it flood tested ? Its a tough spot to be in for both parties, sorry. - best

With that info we can establish a presloped tray. Which will work fine provided the subfloor was level. My question now is at the change of plane where the wall meets the floor and the walls meet in the corner is it grout or caulk? Should be a flexible sealant which would repel water. Your photo appears to be the wettest at the wall floor joint which leads me to believe it is grout. How long does it take to dry? Part of the problem is the marble. Apparently you were not informed of marble discoloring on a shower floor. This is normal but usually around the drain. Apparently Tundra posted as I was typing.

Sorry CTEC! we could also consider The setting material? the dryout and initial cure time before using the shower ... just so many ifs.......

I had a schluter system and my GC contacted a regional rep who looked at our in progress pictures and met with my tiler and GC to determine how to repair. At one point the schluter rep suggested just retiling over just the floor but upon tundra's wise advice my GC and I shot that suggestion down and my GC insisted the shower would be a do over. In case the seepage was coming from behind wall tile and out the floor grout, all the walls and floor tile was ripped out. It could not be determined that the setter had not dot set wall tiles.

However, Upon demo the walls were indeed dry between the tile and membrane so maybe the kerdi rep's suggestion would have surficed. The final verdict was that water dams formed not from preslope perhaps but from excessive lippage in my mosaic floor but I am still not 100percent certain what caused it but it was properly redone and has been functioning perfectly now.

Awesome, guys. Really appreciate the advice.

Was it caulk or grout at the change of planes? This is important.

Looks like grout

BTW Aho on a positive note it is a neat looking shower from the one pic

I have recently discovered a similar problem to the one described above and need some expert advise.

We have a shower that was just put in 8 weeks ago, and the white marble color appears to be "washed-out" or grayish around the drain...maybe more in areas where water strikes the floor directly? The shower has a gentle slope to a central drain...We squeegee it religiously after every use and keep a fan on it to complete the drying process. Is this "graying" of the white tiles normal?

The contractor used the schluter system, sealed the marble, and used "epoxy grout" on the floor. There are no surface cracks, splits, or spaces visible. The tile guy was experienced.

UPDATE: I dried it out a few days (below) but that small gray discoloration in front of the drain remains visible

Can anyone help me? Could this just be the tile taking in a little extra water?