Shower trays not installed according to manufacturer specifications

Hello,

our shower trays are from a German brand manufacturer.
Selected, among other things, because they are floor-level and serviceable.

By "serviceable" I mean that - if we no longer like the shower tray in this color or if it is rather defective (crack / something fell in, etc.) - we could replace it more easily than with conventional installation. (said in layman's terms)

For this, one should (very simply described here) only install the shower trays after the screed has been laid.
Set up the feet of the shower trays, align, align the connections for the drain, etc.
Lay screed
Set shower trays
Tiles

This results in an almost seamless transition between tiles and shower tray.
And the shower tray can be removed more easily later if replacement is needed than if it is fixed firmly under the screed with the edge.

This was done with us (described simply):

Set feet + shower tray + drain etc.
Poured screed (which of course fixed the shower trays)
Laid tiles
But since the screed now comes out a bit higher (according to the sanitary company: the screed trade is to blame)
The tiles also come out higher
Now the cut edge of the tiles towards the shower tray is visible
Therefore, a stainless steel strip was placed around the tiles at the transition to the shower tray (walk-in).
This stainless steel strip is now 0.5 to 1 cm (towards the wall, it becomes this 1 cm) higher than the shower tray.

Guests who visit us always say: "That's great, at least nothing runs out of the shower tray."
But that is incorrect.
Because first, the shower tray is very large and second, it already has a slope,
so that nothing ever runs to the edges.

The visual result is not as desired (seamless transition tile/shower tray)
The manufacturer does not even know this kind of installation (when we asked at the time, but they are always very reserved - always referring to the sanitary company that installed it - but they certainly won't tell us what is correct).

We have withheld a larger amount because we did not agree with the installation of this shower tray as it is.
They would remove the tiles around the shower tray again, grind the screed lower and then re-tile next to the shower tray. We have this agreement in writing.
We should wait 1 year because of the "settling of the shower tray/floor".
Tiles of the same brand were withheld.

QUESTION:
The year will be up soon.
Would you do this / have it corrected?
Won't it make things worse?
If we leave it as it is, we definitely would not pay the withheld amount.
Especially since both (very expensive) shower trays were generally not installed as prescribed by the manufacturer in the assembly instructions: so they are no longer serviceable. (This "innovation" was, however, paid for in the price of the shower tray)

The sanitary company and also (unfortunately) the manufacturer say: There are no specifications. The assembly instructions are a guideline but not mandatory. Is that true?

You buy such material specially and then the sanitary company installs it in the conventional way because they probably have only installed standard until now and cannot do it otherwise.

Unfortunately, one is always wiser afterwards. If we had known before, we would have pointed it out, of course.
But with a master/trade company, you assume they know how to do it.

For us now important:
Do we want to have 3 trades (tiler, screed, and sanitary company) in the house again with the risk that something in the house (staircase, parquet, etc.) will be damaged and/or generally made worse around the shower tray?

Will these stainless steel strips rust over time?
So far, they look fine. But we fear they will eventually start to rust. They are around the shower and constantly exposed to moisture.

If we leave it as it is, we will not pay the withheld amount.
The sanitary company should then get this from the tiling + screed trades.
The sanitary company said they are not at fault.
But shouldn't the sanitary trade that installs the shower tray also be responsible for or check that everything is correctly prepared (in our case: the screed has the correct height, etc.) before the next trade (tiling) is done? Then a correction could have been done at the latest here.

We would also have a legal expenses insurance - if things go really badly, we will also clarify that the shower trays are no longer serviceable like this and this option for later was taken away from us.

There is still time. Due to the current situation, we will not have 3 trades in the house this year and certainly not until next year.

Therefore, we are informing ourselves whether a correction is even sensible.
Actually, we are no longer interested in this.
And the "serviceability" issue would also interest us how you see it.

Or also whether trades do not have to follow the manufacturer's assembly instructions, especially considering that this "serviceability" is a very special feature of the (expensive) shower trays.

Thank you very much for your help.
Rosemarie

If it comforts you, you are not alone with something like that. I chose a shower tray with an integrated styrofoam carrier so that it can be placed directly on the screed without feet. What does the installer do? He builds his own feet underneath... Without photos, I find it difficult to assess your situation. I think you can also calmly name the manufacturer of the shower tray. I would like to take a look at this maintainability. Unfortunately, I have had the experience with another property that the manufacturer does not say whether something was installed correctly. Wouldn't the bathroom floor be uneven if the screed is ground down?

Exactly, thanks for your reply.
Amazing! I really feel sorry for you!

It's a really great cup! We love it.
Don't know if I’m allowed to name the brand here, because of advertising. Better not.
Great instructions included, and I even understand them!

Only the experts apparently don’t.

We also asked ourselves how it is with the floor then: If they remove these 2.5 tiles (they are big 80s) at the edge of the shower tray. Sand down the screed here.
Then it no longer fits connecting to the rest of the floor, which remains untouched by the repair.
I also brought this up. Of course it’s possible... and I still don’t believe it and don’t want any more experiments.

In my opinion, the sample company also bears some responsibility. Because during the sampling we said we want a floor-level tray / everything was discussed.
This company should pass on to the sanitary company (they work together) what the customer's wish is and was specially ordered, and that they immediately take notes that...

But the workflow here apparently runs differently.

Haha, with us it was also the xxx, but without xxx. I looked at the installation instructions dozens of times, yet the installer still said it wouldn't work that way... They still had to take it out again. It's not exactly how we wanted it, but better than before.

Is it a new build with you? Is it handled by a developer, a general contractor, or individual contracts?

Hello Pinky,
thank you for your reply.
It really can’t be that WE have to look at the installation instructions ourselves.

What I/we have learned with the construction (and most of it went really well) is already amazing.

New construction
GU, whose contractual partner is the plumbing company, with which the bathroom equipment is then installed.

I think we’ll skip the rework and keep the money.
Because with rework it surely won’t be 100% and then we would have to pay the money.
We have no energy left to pay THIS company even 1 cent.

I changed it because it is your thread. However, since we are not criticizing the bathtub manufacturer here, nothing should happen. The problem with such defects is often that the proportionality in the remedy must be given. Because of a few millimeters of height difference (I know that is really annoying), it might be too much to tear up the whole bathroom again, especially if grinding the screed seems to be a simpler solution.