Parquet laid continuously without joints

The different temperatures in the rooms are too small to make any difference.

My husband wondered whether the different temperatures (the hallway will be colder than the bedrooms) really matter.

The "working" of wood has less to do with temperature (as with metal or stone) than with humidity. Wood is like a sponge and absorbs water - or releases it - and thus changes its width or thickness (the length changes hardly at all). Whether it is cold or warm doesn't matter. What counts is how much water is in the air.

At the "beginning of life" of a wood product, it shrinks the most ("too" dry wood is rarely processed). After that, shrinking alternates with swelling. And what I have read: this process never ends. Wood "works" even after many hundreds of years.

"Wood lives" :)

It breathes ;)
Sorry, just a gag on the side.
Unfortunately, we had that with our current parquet. Many planks had to be replaced because the ends had partially lifted by up to half a centimeter. Those were real tripping hazards and ouch-toe dangers. The installer blamed the screed and vice versa.
It's wenge, brushed, oiled, planks approx. 80x10.

We suspect as the cause the fact that the planks were delivered on the truck covered with snow before installation. Partly unpacked.

What I consider "advantageous" in this issue is when parquet is installed, meaning there are many joints. Each joint provides a bit of "flexibility." With a width of a parquet block of, for example, 8 cm and a joint width of 0.2 millimeters (so laid very closely), that is 2.5 millimeters per meter. That is already something... The "rest" is then compressed. It is also (conversely) about ensuring the joints do not become too large when the wood is dry. In the above case of the wenge floor, the "transport with the snow" seems to me to be a craft error, but actually rather indicates too large joints (after shrinking) than detachment due to the swelling of the wood. One possible explanation that comes to mind is that there are problems with the adhesive. Exotic woods sometimes cause issues there (although I have not heard that about wenge before, but I don’t know much about it).

Well, if that's the case, it could be that it was "installed shrunk" and then the problems arose due to the expansion.

Before installation, it must be acclimated for at least 48 hours at RT.