Mongo, I've seen many of your posts. I'm very happy you commented. They have installed cement board and a mud bed. The tile installer used some green membrane (first coat here). Do you see any way to proceed from this point or scrap the idea like Letitia suggested above? We were not sure if kerdi could or should be used over this? Would it be too thick for the rough in plumbing to reach the trims? This picture does not show it but the ceiling is sloped. The ceiling backer board has to be redone anyway because they used regular halo LED cans up there. I ordered Mr Steam replacements. I am getting a copy of the TCNA today. Thank you very much! Cindy

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Verify with the vapor proofing / waterproofing product manufacturer directly. That is the only way to assure yourself of a accurate reply. They will also provide you with that response in writing. Just what you need for that conversation with the GC.

Keep in mind that the manufacturers specs will supersede the TCNA Handbook as it is not a legal document. Although it carries substantial weight in court.

Thank you very much! We met with the GC and he is cool with applying schluter membrane over what we have here. I am relieved. A closer look at the green roll on membrane above revealed lots of pinholes and inconsistencies.

"he is cool with applying schluter membrane over what we have here."

That raises a new question. Does the sheet membrane manufacturer approve their product over whichever roll-on membrane that is already on the cement board?

Which specific type of setting mortar would be required to bond the surfaces?

Always get the manufacturers blessing to eliminate risk. IMO.

You are dealing with vapor proofing and perm ratings as Mongo CT mentioned above. There are many sheet membranes on the market. Laticrete. Noble, Mapei, Ardex, Schluter and more. It would be to your advantage to do some research comparing those ratings. Unfortunately folks on Houzz have bought into one manufacturers marketing and blinded themselves to some superior and more cost effective options.

Your vaporproofing MUST be bonded to the drain flange topically at this point in their progress. You do not want a mix match compromise here. DRAIN is already buried and doesnt have a 2" bonding flange.

IMHO. you need to stop and back UP .

UGH! We insisted on schluter waterproofing because the tile guy didn't seem to understand the requirements for steam. We thought it would be our best bet for success and no one cutting corners by eliminating a coat or two of the red guard (green guard). We already purchased the steam unit, so felt we should proceed.

The schluter and ditra mat were applied.

The tile guy is inexperienced with large format tile. When we arrived he was down to 1 tile and was pounding it with a rubber mallet until it broke. All the rest were lying around with one cut or broken off at the corner. we ordered 32 tiles for this shower. He forgot the niche I bought and didn't use the large format mortar we bought. He used regular thin set.

We told the builder that we did not want this guy to continue. Now we are able to see that there are huge gaps in the mortar on the sides of the tiles. The builder and his other more experienced tile guys say this is ok. He doesn't want to demolition this and start over. The builder maintains his technique is to apply mortar in splotches so he doesn't have too much squishing out. i I have I have to disagree that vapor can get behind the tiles now. How do you make up for these huge gaps? grout?

I'd like to hear from unaffiliated experts. Thank you very much! Cindy

The broken tile removed on left. Right tile removed because he forgot to install the niche.

This is around the switch for the steam controller.

One of the tiles that was removed.

Poor cut here, very frustrating.

Wrong thinset is a do over 100%, the tile will fail without the proper LFT thinset. In a steam shower those tiles will require 100% coverage with the thinset or they will fail. Up to you if you want to accept his BS excuse, just know that this will not hold up.

Stop. Spot bonding is unacceptable PERIOD.

95% minimal coverage in a wet area is required. You can do something wrong for twenty years and it's still wrong. Sorry but these are the facts.

The builder and his tile guys keep telling us it is not going to be "perfect" as if our expectations are too high. We want it done correctly without ruining our relationship. We still have a way to go on the rest of the house. Thank you both very much! Hopefully we will find the right words.

Shove a copy of the bible of industry standards under his nose. Then he is arguing with the TCNA, and not you. My 2022 copy just arrived, and its also on the website to purchase.

https://www.tcnatile.com/products-and-services/publications/218-english-publications/188-handbook/983-2022-tcna-handbook-for-ceramic-glass-and-stone-tile-installation.html

yes, sir! thank you very much!!

Would anyone be willing to give advice on preserving the tile floor after demo of the walls and ceiling? During the demo the detra mat was dislodged on one side. After further inspection we realized there were areas of too much thinset and not enough between the detra and floor tile. The new plan is to tile over the existing floor tile as not to disrupt the "plumbing"

I suppose they mean the shower pan. Is it possible to do this? If so would they lay down another detra mat on top of the old tile and go from there? They are planning to replace the schluter wall

waterproofing membrane. We did not have the schluter drain system with the detra.

I am afraid we will end up with a lot of nooks and crannies of water in this old floor tile. If we have to go this route what should be the subsequent layers on top of the tile? We can probably insist they demo the floor but if this is a viable option it will save alot of time and money.

On another note, Mr Verbo and Mr Creative TIle, I got the TNCA manual. I'm having a hard time finding where is says specifically to mortar and back butter 95-100% of the tiles used in the steam shower. I found that information on the large format mortar instructions bag. I was hoping to find it specifically written in the manual because it will be harder for the builder to refute the manual vs the mortar package. I do know how to read but it seems pretty technical for me.

Any input is MUCH appreciated. Thank you! Cindy

Every bit if that has to come out and start over with a different contractor. Just take this out of the scope of work under the current GC, and subtract 25K to have it done by someone else who has done this before. If the waterproofing and framing isn’t done correctly, I doubt the electrical and ventilation is either. Water and electricity can kill you. Do not take that risk.

@Cindy Everett that's not going to work, unfortunately. You're going to have to pull the floor too; mixing and matching part of a pan liner method with ditra indicates a misunderstanding of how these systems work. In fact, I'm trying to understand why they would have even tried that. Is this a curbless shower?

Re: 95% coverage, you'll find it on pg 37 in the 2022 TCNA manual. Back buttering isn't always specifically required, but for many tiles it's needed to achieve full coverage.

Thank you very much, the builder and tile guy both say they’ve done steam showers before. The tile guy says he’s coming of a steam shower project to ours. Can’t imagine what materials and methods were used.
It is not a curb less shower. We had to part ways with the original builder. He did not listen to our request for curbless, so here we are.

I’ve been following for months. Did you get the steam shower done? What method did you use?

Thank you. I don’t think anyone involved on our project has done a steam shower like they said. I say this because we had to be very involved. We aren’t experts but we can read. We demo’d down to the dietra mat. The GC refused to take out the mud bed and liner. The tile guy used schluter fabric for the walls and ceiling over cement board. i will post a picture. We are waiting on glass to be installed. Hopefully it’s steam tight.

Thanks!!!! My project has stalled for over 6 months because I can’t find anyone who knows how to do a steam shower. I have been educating myself so thanks for sharing. I must get this done asap. What steam generator did you buy?

We got the basic Mr Steam butler package. Is this a new build or remodel? Are you in NC by chance?

I am in NYC. It’s a remodel.