walk-in shower

Dear forum,
hopefully I am in the right section. I bought a condominium and hired the plumber to install a 3cm 90x90 shower tray for me. I discussed this with him before the screed was laid. He wanted to put a board in place so that the screed would be recessed and the tray could be lowered. Now it has turned out that this was forgotten. The tiler now says that nothing will come of it, the tray will protrude by 1.5 cm.
My question: one would now have to remove an area of 90x90 minus the hole for the [Traps] 30 x 30 about 2 cm deep, do I have a chance? Grinding away will probably not work, or can this be accomplished with a milling machine?
Thanks in advance
Best regards Frank

Hello Frank, is underfloor heating installed in the shower area? This should be taken into account when removing it! Then you could use a cutoff saw to cut around your "hole" and then try to chisel down to the Styrofoam (the plumber should actually take care of that...) No compromise, you'll be annoyed for years.. Best regards Jens

Hello Jens, yes, there is underfloor heating installed, I think about 2cm would have to be removed. The plumber is definitely responsible for that. Since I have generally had legal disputes, in a serious case I will have to do the work myself. I also thought maybe to cut grooves with the angle grinder + stone disc and then carefully pick out the strips on the side? Best regards Frank

...that should work, is it anhydrite screed? It's usually quite thin... Take a look at how thick it is planned to be. Are you sure 2cm is enough?

Best regards
Jens

don't know if this is anhydrite screed. This is a shower tray from Hoesch, it is 30mm. The tiles with adhesive are 15mm, then a bit of silicone under the tray, I think 20mm will be enough.

Best regards Frank

The plumber is definitely responsible for that. Since I have generally already had legal disputes, I will have to take matters into my own hands in a serious case.

You are not supposed to start a legal dispute with him, but rather ask him for remedy and have him fulfill his contract. If you start working on the screed yourself, you may waive more warranty than you would like.