Experiences with cork and underfloor heating?

Hi,

we are currently stuck on the floor coverings for our new building and have now come across cork and its very positive properties. I have already read that cork tiles are preferable to cork click parquet due to better thermal conductivity.

I also read that the underfloor heating must be adequately dimensioned for this and that a humidifier is actually needed to ensure 50-60% humidity. Also, 20 degrees would be important... Huh??

Just asking around: who has cork and what are your experiences?

It is nonsensical to lay an insulating material = cork on underfloor heating. Cork does not have a "better thermal conductivity" but a very poor one. Therefore, it insulates very well and is perceived as warm underfoot, for example. The thermal conductivity value is 0.035-0.046 W/mK. This makes cork a genuine insulating material. Ideal for underfloor heating are materials with very good thermal conductivity: tiles, polished screed or concrete, natural stone slabs, metal. Even parquet or tongue-and-groove flooring over underfloor heating is borderline.

Decisive for the suitability of the flooring for underfloor heating are, on the one hand, the thickness of the material and, on the other hand, its thermal conductivity. These two determine the thermal resistance – the lower this is, the better. The thermal resistance of 0.15 m²K/W must not be exceeded. To calculate this, the entire structure above the underfloor heating must be taken into account. Any specialist company for floors or heating/sanitation should be able to perform this calculation.

I have cork flooring on underfloor heating. It’s great. But directly glued onto the screed, only 5 mm thick. So a thin layer that still feels elastic and is great both in winter and summer. Whether you choose parquet, laminate or cork is almost irrelevant, depending on the construction they all generally have poorer thermal conductivity than tiles / natural stone. It rather depends on the thickness + installation method.

20 degrees = presumably the maximum permissible temperature for the floor on underfloor heating. And yes, humidity is important for a natural product. This also applies to solid wood furniture or partially solid wood. Otherwise, the wood could become cracked.

Cork does not have a "better thermal conductivity" but rather a very poor one.

It was meant that in connection with the underfloor heating, cork flooring boards should not be used, but directly glued cork panels. The construction above the screed will then be about 5 mm thick (see also #3).

I know households with cork flooring boards. There it also sometimes gets warmer than 20 °C, and there are no special precautions regarding humidity. Since the surface is sealed, I wouldn’t worry too much about it.

We are currently building with underfloor heating and cork (directly glued). Moving in summer. So in about 2 years I can report my own experiences. It will be fine ...