Too cold to install the underfloor heating?

Hello everyone,

we are currently building a house using timber frame construction and it already looks very good!
Now the ventilation, water, and electrical lines have been installed and only the underfloor heating is missing.
It was supposed to be installed yesterday. However, the construction manager told me that it is too cold for that.
The house itself has been standing for 3 weeks and has been completely closed with windows, etc. since then.
All trades have been working quickly and carefully so far, and even the chimney builder or the plasterers on the facade had no problems with their "masonry work" due to the temperatures.

Are the heating loops really that temperature-dependent? The outside temperature here is at least -3°C, mostly above freezing during the day. Previously, it was always clearly said that one would be independent of the weather since the roof is immediately put on.
As a layman, I could understand that with the screed, but the pipes could already be laid, right?
...but I don’t want to accuse anyone of anything...

Of course, I am quite impatient right now... :-)

Best regards

All trades have always been quick and careful at work until now

Then there is no reason to rush now or to distrust anyone.

How warm is it in the house? If the hoses are made of PE, it actually gets pretty bad below 5°, as they become very stiff.

After installation (before the screed is applied), the tightness is tested with a pressure test. To avoid frost damage, it should not be too cold. The material is also very stiff due to the cold; it is better if it is not so freezing cold.

How cold exactly it is in the house I don't know (feels warmer than outside). If the hoses are really too inflexible then, I am relieved. Unfortunately, it doesn't look like it will get warmer again within the next 2 weeks... :-( It just made me a bit suspicious because it was always emphasized how independent you are from the weather... too bad, waiting really isn't my strength!!!

Come on, I'm building a house for the next 30-50 years, ideally even longer. So it surely won't fail because of a week, a month, or in the worst case even 6 months.

Get used to it, because the screed and plaster are still missing.

In the long run, it's better if everything can dry longer than always just the technical minimum time. And what good is a poorly installed underfloor heating where the installer is cursing forever and the workmanship is weak. You want to heat with it for many more years.