Granted I'm not doing this myself. This is more a question of if the job was done properly. I hope that's not against the rules.

We recently built a house and moved in 3 months ago. There was an issue with the shower not being centered on the wall so we are in the process of having it repositioned 3 inches tot he right. The tile guy took off three tiles. Then the plumber came in and cut through the wall to access the pipe to move it over 3 inches. Easy enough.

However, the tiler, I don't believe, put up any more drywall or cement board or anything over the holes that were cut when he put up the new tiles. It looks like he did put some Kerdi membrane down where the valve is and put the thinset over that. But where the shower head goes, I think he just put some thinset around the hole and stuck up the new tile with no drywall/cement board or membrane. I can stick my finger in the hole in the new tile and move it around without touching anything--no drywall, no membrane.

Here's some pictures: https://imgur.com/a/xqHJw

My concerns are:
1. First, is the original construction a proper installation in the first place? It looks like it's Kerdi over drywall. You can see in the photos where the plumber cut it open that it appears to be drywall. My research tells me drywall should be used as a last resort. I didn't really give it a second thought until I started researching this issue.

2. Secondly, the fact that the tile guy is now just putting up new tile without filling in these cut-out holes or using enough Kerdi has me worried about future water damage and mold. With my limited knowledge it seems like shoddy work. Am I overreacting?

 

Hard to tell..... is that just sheetrock ?
Cement board would be the norm now.

Is that bench made of sheetrock with metal corner bead ?

 

The only thing that throws me off is the fact that it's a darker grey compared to the rest of the drywall in the bathroom. As if it's not typical sheetrock. But looking at the cross cut that the plumber did, it definitely looks like sheetrock.

 

It's certainly a cleaner cut then cement board would be.

 

That appears to be DensShield tile backer. It is similar to cement board but a lot easier to work with.

 

In the last picture it looks like there is the orange Ditra membrane.

Upper tile looks ok, the lower pieces looks questionable for support!

 

I bet you're right. Thanks