New floor construction in the old building. Parquet instead of new planking?

Hello everyone,

we are currently renovating a 100-year-old house and wanted to refurbish our floorboards. Unfortunately, we had to discover severe worm damage and many defects.

The floor structure is a reinforced concrete ceiling. Below it is an uninsulated cellar. Insulating the cellar ceiling from below is not possible. On top of it is a substructure with filling and 3cm spruce floorboards.

My husband is now more enthusiastic about parquet, but how could the floor structure look here?

At the beginning, we had a specialist for old building renovation on site and he said that we should definitely not lay any foil on the floors. So that everything can continue to breathe from the cellar.

However, I now do not imagine OSB board plus cork insulation plus parquet to be optimal over our cellar ceiling?! Is OSB diffusion-open? Is there a risk that mold will start underneath?

Thanks for advice and help

Hello questioner. I also have a question regarding your questions: "The floor structure is a reinforced concrete ceiling. Below is an uninsulated cellar. Insulating the cellar ceiling from below is not possible." I consider that possible, but the question of WHY NOT should be answered in a comprehensible way! Because due to the relatively extensive renovation, you are legally required to comply with the Energy Saving Ordinance! ------------------- "At the beginning, we had a specialist for old building renovation on site, and he said that we should definitely not lay any foils in the floors. So that everything can continue to breathe from the cellar." Nothing breathes in or above the cellar. What the specialist meant is that no waterproofing or vapor barrier should be installed. That can certainly make sense (not installing sealing), if the thermal insulation is missing. Otherwise, you would have condensation on the foil (and thus inside the living space)! So far, a correct answer. The core issue thus remains the question of thermal insulation! ----------------------- (1)"But I can’t imagine OSB board plus cork insulation plus parquet as optimal over our cellar ceiling?! (2) Is OSB vapor-open? (3) Is there a risk that it starts to rot underneath?" Answers: 1: YES, correct. 2: No 3: YES (+ very likely condensation formation) ---------------------- A recommendation for the structure without detailed knowledge of the object is not seriously possible. Any solution along the lines of "... we also have ..." can never lead to a damage-free result because all marginal aspects must be precisely taken into account!!! Regards: KlaRa

Thank you very much for the response and the already helpful information.

Our basement is only just under 170 cm high and all the piping runs along the ceiling.

If we were to take up the entire floor, it might be possible to insulate the cavities?! We have now heard of glass gravel or possibly also wood fiber insulation?!

If we were to remove the entire floor, it might be possible to insulate the panels?! We have already heard about glass gravel or possibly also wood fiber insulation?!

In principle, incorporating thermal insulation into the panels is a good idea!
However, the effectiveness depends on the possible insulation layer thickness (thus on the depth of the paneling). For example, if a 10 cm insulation thickness (W035) were possible, you would have "won."
The principle is as follows:
Moisture comes from above (from the living area), cold comes from the basement. Simply put.
If the thermal insulation can be installed as widely as possible, a well-effective vapor barrier (PE film, at least 0.15 mm thick, overlapping and taped 30 cm at the edges of the sheets) should be sufficient. This would mean that the load-bearing beams and panel chambers are continuously covered with the vapor barrier.
Depending on the evenness of the load-bearing beams, OSB prefabricated panel elements (that's what they're called) could then be laid on top on impact sound insulation strips as a subfloor for, for example, PVC planks or a multi-layer parquet (on a thin felt layer).
Glass gravel is completely unsuitable here.
This material is suitable under concrete floor slabs as a capillary-breaking layer and simultaneously as thermal insulation (if you have the necessary excavation height, as in new construction).
---------------------------------------
Best regards and good luck: KlaRa