Very messy parquet laying work - Is rework not possible?

Good that there are enough craftsmen and service providers who know exactly what customer satisfaction and professionalism are.

I am happy to repeat my post and thus the question about the building components.

Is that a concrete staircase with an expansion joint to the concrete ceiling?

Just because the young craftsmen ignore the technical standard to satisfy customers does not mean that it is correct.

Acrylic is certainly not professional, as it is not elastic. Expansion joints must be closed with elastic filler. So it may be reputable among laypeople, but acrylic joints for parquet - nope.

Presumably, the images show permanently elastic joint sealant, but since laypeople cannot distinguish it and hardly know anything other than silicone and acrylic ....

I refer to the statement paraphrased by the OP from the renowned parquet layer:

In the window area, it is cut sharply and sealed with acrylic in wood color.

In the pictures, I am sure that proper joint filler was used. The joints are a bit large; as far as I know, with fully glued parquet, the joint should be somewhat smaller. And yes, more effort could have been put into the choice of joint filler color.

I refer to the statement paraphrased by the OP from the renowned parquet installer: In the pictures, I am sure that proper joint filler was used. The joints are a bit large, to my knowledge, with fully glued parquet the joint may be somewhat smaller. And yes, more effort could have been put into the choice of the joint filler color.

Sure, acrylic, silicone, joint filler – as a layperson one cannot always distinguish the technical terms and might possibly use the wrong term. The important thing is that it is simply poorly executed. All expansion joints are too large, crooked, and unnecessary. As I said, there are enough craftsmen who do it aesthetically well and are not stuck in 1980. And yes, thank God, there are many modern young craftsmen who constantly educate themselves. Let’s see how the follow-up appointment goes. What is certain is, if he can’t do it, someone else will.

Use your energy to eliminate the visual defects. In my opinion, a legal dispute is hardly winnable.