Solid wood parquet on underfloor heating

since I basically have a good feeling about the company

A rarely mentioned, but in my opinion not unimportant argument in craft contracts: "Which technique does the craftsman prefer?"
That affects the care taken when working ... and whoever likes doing what they do works better than someone who was persuaded to do something else. And maybe the craftsman even masters this technique better.

If one cannot be glad at all these days to get a craftsman with professional training,...

A rarely mentioned, but in my opinion not unimportant argument in craft contracts: "Which technique does the craftsman prefer?"

Thank you very much for your opinions and tips. Somehow it still doesn’t leave me in peace. I had a bit of further reading. In floating installation, it is mostly also written that parquet cannot be sanded and generally wears out faster, as the connections between the planks are more stressed. You also read everywhere about sound transmission up to creaking floorboards. I just wonder why he suggests it for my screed. It could be that he generally prefers floating installation or that the subfloor is really that bad, which I don’t believe at least for the living room. And he wants to resin the crack in the screed anyway (for floating installation that doesn’t make sense to me). Secondly, I wanted to ask? Whether you need these baseboards everywhere between the rooms in floating installation or if you can also run through. He said that’s necessary. He also wants to possibly, if necessary, make a joint/board in the living room, there was previously a silicone joint between the tiles. But that just doesn’t look so great in the middle of the room with anodized aluminum, I think.

I am not the craftsman who has learned "how it’s supposed to be done," but I am happy to share my experiences. What comes to mind regarding your questions: Cracks occur where something moves and is simultaneously held fixed elsewhere. A crack in the screed means that such stresses exist there. Filling it does not help against the movement. The movement arises (among other things) due to the different dimensional changes of materials... and that does not stop at some point but always remains. A bridge must be made over the crack (I believe fiberglass mesh is often used) so that the movement is absorbed. When it is clear that movement cannot be prevented, a joint is made, which then does not form randomly somewhere but is located at a planned spot. "Floating installation" prevents the stresses from the screed from continuing into the covering (and causing cracks there). But if the floating area becomes too large, there will also be stresses (and possibly cracks) INSIDE the surface material. For example, when wood is glued to concrete, the wood will crack or its joints will open because it "moves" more than the concrete. To make the wood adhere to the concrete at all, you need adhesives that are a bit elastic. (This is used conversely, for example, with tiles on wood.) Such problems are not "always the same." There are situations where something works that fails elsewhere. That is why one plays it safe (even though it might also work differently... but you don’t always know that 100% beforehand).

With floating installation it is usually also written that the parquet should not be sanded

In my entire life I have never met anyone who sanded down his installed parquet. So far only in old existing houses.

and also generally wears out faster because the joints between the planks are more stressed

That is nonsense. Wear comes from walking and dropping things, etc.
You don’t use the parquet differently just because it is installed differently.

You also read everywhere about sound transmission up to creaking floorboards.

The sound of floating installed parquet is indeed different. I don’t like it either. But creaking floorboards should not occur.

Whether you need these finishing strips between rooms everywhere with floating installation or whether you can also do without. He said it is necessary.

I agree with him.

He also wants to possibly make a gap/strip in the living room if necessary; there was previously a silicone joint between the tiles.

Depends on the size of the room.

Hi everyone, it will probably be installed as a floating floor. Due to the thin wear layer of 2.5 mm and ultimately the strong persistence of my floor installer, we are now doing it floating. Still, I have two questions: Is floating installation at a disadvantage if water gets on the parquet (we also have it in the dining area)? For example, a glass could be knocked over there. I'm just afraid that the water would then spread, for example, under the impact sound insulation. With glued parquet, this would only be possible to a limited extent. Secondly, if you ever have to replace a plank because, for example, the top layer detaches, that's easier to do with glued parquet, right?