Ceramin tiles/tiles (Company Classen) not fully covered with putty

Hello construction workers,

how would you assess the situation: My tiler did not fully bond the new Ceramin Tiles from the company Classen (400x800). At the joint in the half-bond pattern and also at the side joints, it often sounds hollow when you tap on it. The feeling when walking on it is therefore not pleasant, especially when walking barefoot. The tiles therefore have no contact with the old tile floor in several places (see photo). Is this a cardinal error of an experienced tiler, or does the saying apply here: When the craftsman starts to think. I am very dissatisfied with the situation. Unfortunately, the new kitchen is already installed on top. And tearing it out would be very complex and expensive. Underpinning is also not possible because the joints are only about 1mm wide. Drill holes would be visible. And underpinning would be necessary almost everywhere.

What options or rights do I have here as a client?

Thank you very much in advance.

The feeling underfoot is therefore not pleasant, especially when walking barefoot over it.

What am I supposed to imagine from that? Does the tile bend (then the joints would already crack now) or is it just the noise? I would expect that if you hold your ears, you wouldn’t notice anything from the missing adhesive.

My tiler did not fully bond the new Ceramin Tiles from the company Classen (400x800).

Do you happen to have photos of the installation to see how much adhesive is actually applied?

What options or rights do I have here as a client?

It depends. Namely, whether there is sufficient adhesive or not... That can only be determined with pictures and/or by removing tiles. A defect exists if the usability is not given. Exactly how many spots or areas in sq cm are we talking about? Have you already accepted and paid for the work? Or reported a defect to the tiler?

Hello "Benutzer210".
First of all, it must be known that a cavity-free installation of tiles and slabs is already difficult to achieve due to the permissible flatness limits of the installation substrate (the screed surface).
This means that cavities, generally speaking, do not necessarily constitute a "defect" (a legal term, the assertion of which should be avoided by non-lawyers).
It depends on the extent of the hollow areas whether a complaint can be made or not.
However, the large tile size of 80 cm x 40 cm raises questions.
What type of Ceramin tiles are these? Megaloc or easy-lock?
The (in my opinion weak) installation instructions do not indicate that a dispersion adhesive, as is usual for tiles and slabs, is to be used here, but that the tiles are provided by the manufacturer with a dry adhesive on the back.
If you further look at the product information of the product type "Ceramin", you quickly come to the conclusion that, due to the "fast installation system" mentioned there, it cannot possibly be a type of flooring known as "ceramic covering".
This is also confirmed by the note that it contains 10% recyclate.
To summarize briefly, due to the tile format, a higher surface flatness of the screed is definitely required!
There is no way around it, even with purely ceramic tiles.
That means: grinding, vacuuming dust, priming, and applying a leveling compound.
If this has not been done, the installer should be asked why not.
Because in connection with a dry adhesive on the back and surface unevenness, a full-surface installation of whatever it is is impossible.
With ceramic slabs, even with the large format, one would have to switch to a medium-bed adhesive, since a thin-bed adhesive must fail with sufficient certainty.
In conclusion:
If the floor covering elements can be slightly pressed toward the installation plane under pressure, if slightly audible "smacking noises" can also be heard, or if the pressed-down surface of the element bends back up after a short time, then it is time to involve the installer and ask for clarification.
(obtain all product information beforehand that the market or the internet can provide so that you have a basis for discussion!)
---------------------
Good luck: KlaRa