ᐅ Screed / Moisture Measurement / Underfloor Heating / Expansion Joints

Hello forum community,

Since I couldn’t find any answers using the search function or by browsing the forum, and found only sporadic information online, I decided to create a new topic.

I am in the process of buying a condominium and have a few questions regarding the title topic.

The apartment has underfloor heating installed, but it is not yet connected. The building was constructed in 2014, so the screed (I’m not exactly sure what type) has been in place for several months. In the middle of the living/dining room, there is a hole with plastic rods that, I was told, is for measuring moisture later on.

As a non-expert, I asked: Shouldn’t the underfloor heating be run at high temperatures for several weeks to dry the screed, to prevent any cracks once the floor covering is installed?

I was told that there are expansion joints around the edges, so that won’t happen.

Is it possible for the screed to be dry after the “colder season,” even though the apartment has never been heated?

What is correct or incorrect about this statement?

Thank you in advance for your help.

Best regards,
Jerome

The screed can also dry out during the cold season. It essentially hardens. The information about the expansion joints is correct – assuming the screed is installed properly.
If you have a low flow temperature for the underfloor heating, the floor should not expand even at 30°C (86°F) underfloor heating temperature.

Thank you for the quick response. So, I could have the tiler do everything, and then only turn on the underfloor heating when moving into the apartment?

The functional heating should definitely be carried out beforehand.

Koempy schrieb:
The functional heating should definitely be done beforehand.

So, functional heating must be carried out before installing the floor coverings. Or is that what is called drying-out heating? Somehow, I don’t really understand the basic difference!

Since the heating system apparently has never been connected and will only be when I purchase the apartment, this confuses me, but the builder should actually have done this beforehand.

I would have the floor coverings installed by the builder for a fixed price, and I would supply the materials.

I’m quite suspicious about this now 😕

Functional heating means testing the function of the underfloor heating system. In my opinion, whether there is a floor covering on top or not is irrelevant. You can also skip the surface heating stage by allowing a long drying time, as this is mainly about removing residual moisture. If your moisture levels are below the recommended values, it should be fine. However, I am just an amateur,...