120x120 tile / piece broken

I would like to refer again to the [Bauleistungsversicherung]. If no craftsman gets in touch, it is this insurance that comes into play. After all, that is what you pay your insurance premium for. And then you might as well have it repaired properly.

I totally agree with Buchsbaum. That can be very easily repaired again.
For me, the tiler had to redo 3(!) tiles (well, "only" 30x80) but he did that alone in 1 hour. €1000 is not justifiable, not even for this size.

If the tiles are to be replaced, the price can almost be correct.
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The craftsman might not even have liability insurance and is hiding the damage. Nobody saw it.
It wasn't the tiler. Therefore, there is also no person responsible for the damage whom you can hold liable.

That is basically correct, but "one" in this case is the tiler and not the OP. Because as long as the work is not accepted, it is the craftsman's problem. The OP could therefore document the defect in writing upon acceptance and insist on rectification. She has the right to a defect-free work.
That is super annoying for the tiler. But he can also glue it and doesn’t have to replace it. That would probably be considered acceptable.

@ "Sonneneck":
The situation is simpler than one would expect!
You are the client, the tiler has accepted the contract.
He is not only obliged to deliver a trade that complies with the current professional standards, but also to protect his trade (here: tiling and panel works according to DIN 18352) from damage until acceptance.
Whether this is possible in every case is a matter to be left aside here.
Now, the tiler can demand to receive the agreed contract price for his properly executed trade.
However, the trade is not properly executed because some tile edges are damaged.
If you have not yet paid the contract price after receiving the invoice, then the risk, as it is said, lies with the contractor.
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In brief:
Registered mail to the tiler stating that the service is defective due to edge chips on several tiles and that therefore the contract price is not due.
Request for rectification within a 2-week deadline.
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(This is not legal advice!)
Regards: KlaRa

to protect against damage until acceptance.

I see it a little differently. It may be that he has to protect his work. But if he finishes work at 4 p.m. and late in the evening other trades damage his work, then he can't protect it as he should. The tiler then has to report the damage to his work to the client.

If, say, I install a door at a customer's, plan the acceptance for the next day, and the client then dents the frame in the evening because he was still moving furniture, he can't just demand a new door. How far is the duty to secure supposed to go?
Should I, as a craftsman, then hire security or what?

I see it a little differently. It may be that he has to protect his work. But if he finishes work at 4 PM and late in the evening other trades damage his work, then he can't protect it as he should. The tiler then has to complain about the damage to his work to the client. If, say, I install a door at the customer's place, plan the acceptance for the next day, and the client presses a hole into the frame in the evening because he was still moving furniture, then he can't demand a new door. How far is the duty of care supposed to go? Should I as a craftsman then order security or what?

You are welcome to see it differently. But that is (unfortunately) only your personal and insignificant opinion. Your example is extreme, but in fact, the customer would be entitled to a new door. Period. No matter how crappy that is, it is correct. Formally correct is the statement from . Until acceptance, it is indeed the contractor's problem. He could at most have his client's claims against the party causing the damage assigned to him (Building Code §255), but then he must know the perpetrator and also prove that it was them. Otherwise, there are insurances for such cases for the contractor.

KlRa has named the corresponding guidelines. As I already said, each trade is responsible for protection until acceptance. That is why many floor layers also lay down thick paper or something similar on their own initiative. Carpenters protect the doors with foil or foam, etc. Often not, because the effort to stick something everywhere again might be greater than potentially just replacing a door leaf. Or because in practice they agree on a defect discount of 100-200 EUR. Or because they know that in practice it is not enforceable. Which private builder will wait up to a year to move in because of damage worth 200, even 500 EUR? - exactly: none. That is what I meant by a complete replacement not being enforceable. Either accept a cosmetic repair or accept a defect reduction of about 250 EUR. Nothing more will come out of it. Since the tiler was commissioned separately here, the use of the property is not blocked. So you are welcome to try it through legal action. But it will probably be dismissed as a trivial matter, I would suspect.