Experience with 3cm thick terrace slabs - do they break?

Would it be an option for you to keep the plates in stock? Although it’s also rather difficult to manage with 3cm given the size, you don’t have the problem of wobbling.

We have 80x40 and the plates have been lying in the gravel bed for a year. What is very important is that they always have proper joint sand in them. I missed this a bit this year, and they started to wobble slightly. Swept it back in well and the problem was solved. The problem is the ants, who love that stuff. You have to keep on top of it. We deliberately only had them placed in the gravel bed for now because we want to test the plates (very light) first. If we are still satisfied in 3 years, they will be taken up and firmly installed.

We laid our tiles in a drainage mortar bed and have had no problems with it so far.

Best regards
Sabine

We decided against a ground slab because we were not exactly sure how far the terrace should extend and whether we wanted stone or wood. Now we want stone, have found a beautiful slab for us, and are now facing all the new problems. Thanks for your experiences. I had hoped that [Fugensand / Quarzsand] could be the savior. Laying it in the mortar bed is again so labor-intensive, expensive, not easily replaceable, and carries the risk that it will still freeze and crack open.

The entire project stands or falls with the [Untergrund]. Highly compacted and then a minimal gravel bed and firm edging will work.

But that contradicts the other experiences mentioned here...
By fixed edging do you mean lawn edging stones?