So I've confirmed the white is thinset. I guess they can scrape it out or enough of it out to allow sufficient depth to re-apply the gray grout and cover it up. It's a cosmetic issue.
On the wet spots on the bottom I've learned a fair bit more and could use some further feedback from the community...
The wet spots basically stay darkened and seep water for 3-5 days after usage. (we started using the other shower for now). After a couple days - I applied a heat gun and got the wet spots to go away (temporarily). Checked an hour later and it was dark again and ever so slightly damp. But after 3-5 days - the spots get dry, lighten in color and stay dry. That is until the shower is used again. And so on. There are no water lines in that wall either.
My theory is that water is getting behind the grout up above and somehow running down thru whatever channels it can find and pooling lower where it eventually seeps back out over time... Purely speculation on my part.
I found one particular gap about 2 or 3 inches wide a couple courses directly above the wet spots occur and I can actually see blue backer board where the grout is missing. Not only could water get in there but if there's not any visible thinset - that would indicate cavities behind the grout... If this is the same in other areas - there could indeed be channels the water might run down to the wet spots below...
I also see about 20 inches or so in total where there's some cracking and the tile is not making contact with the grout - I'd call it 'shrinkage cracking' except grout doesn't or shouldn't shrink as far as I know. And there's one area where the grout doesn't seem particularly hard. When dry it's crumbly to the finger touch and when wet it's 'pasty' to the finger touch. Very strange.
Mapei grout.
I think I'm going to request they remove/re-grout suspect areas above. And I think they'll be willing to seal it too (don't know how long sealer works). And I think I'll ask that they leave an inch or so of the worst offending wet areas below alone. That way if we fix the problem above, I can see if the area below drys out normally or stays wet. If it dry normally that woudl suggest the problem was fixed above and I can come back and touch up that last bit myself later.
" guess they can scrape it out or enough of it out to allow sufficient depth to re-apply the gray grout "
All changes in plane are to be silicone caulk, never grout for that exact reason.
" My theory is that water is getting behind the grout up above and somehow running down "
Your theory is incorrect, grout is not nor was ever intended to be waterproof. Water gets thru there constantly. You issue with the standing water is the pan is not pitched properly most likely and that will never change without tear out. The floor was not built properly BEFORE the tile was installed.
" and I can actually see blue backer board where the grout is missing. "
What was the "blue backer board" As asked earlier, what was the waterproofing system used?
" I also see about 20 inches or so in total where there's some cracking and the tile is not making contact with the grout - I'd call it 'shrinkage cracking' "
Your shower is not constructed properly and you are not "fixing" this. It will only continue to get worse and worse.
So I've confirmed the white is thinset. I guess they can scrape it out or enough of it out to allow sufficient depth to re-apply the gray grout and cover it up. It's a cosmetic issue.
On the wet spots on the bottom I've learned a fair bit more and could use some further feedback from the community...
The wet spots basically stay darkened and seep water for 3-5 days after usage. (we started using the other shower for now). After a couple days - I applied a heat gun and got the wet spots to go away (temporarily). Checked an hour later and it was dark again and ever so slightly damp. But after 3-5 days - the spots get dry, lighten in color and stay dry. That is until the shower is used again. And so on. There are no water lines in that wall either.
My theory is that water is getting behind the grout up above and somehow running down thru whatever channels it can find and pooling lower where it eventually seeps back out over time... Purely speculation on my part.
I found one particular gap about 2 or 3 inches wide a couple courses directly above the wet spots occur and I can actually see blue backer board where the grout is missing. Not only could water get in there but if there's not any visible thinset - that would indicate cavities behind the grout... If this is the same in other areas - there could indeed be channels the water might run down to the wet spots below...
I also see about 20 inches or so in total where there's some cracking and the tile is not making contact with the grout - I'd call it 'shrinkage cracking' except grout doesn't or shouldn't shrink as far as I know. And there's one area where the grout doesn't seem particularly hard. When dry it's crumbly to the finger touch and when wet it's 'pasty' to the finger touch. Very strange.
Mapei grout.
I think I'm going to request they remove/re-grout suspect areas above. And I think they'll be willing to seal it too (don't know how long sealer works). And I think I'll ask that they leave an inch or so of the worst offending wet areas below alone. That way if we fix the problem above, I can see if the area below drys out normally or stays wet. If it dry normally that woudl suggest the problem was fixed above and I can come back and touch up that last bit myself later.
Anybody have a better idea or input? Thanks!
" guess they can scrape it out or enough of it out to allow sufficient depth to re-apply the gray grout "
All changes in plane are to be silicone caulk, never grout for that exact reason.
" My theory is that water is getting behind the grout up above and somehow running down "
Your theory is incorrect, grout is not nor was ever intended to be waterproof. Water gets thru there constantly. You issue with the standing water is the pan is not pitched properly most likely and that will never change without tear out. The floor was not built properly BEFORE the tile was installed.
" and I can actually see blue backer board where the grout is missing. "
What was the "blue backer board" As asked earlier, what was the waterproofing system used?
" I also see about 20 inches or so in total where there's some cracking and the tile is not making contact with the grout - I'd call it 'shrinkage cracking' "
Your shower is not constructed properly and you are not "fixing" this. It will only continue to get worse and worse.