Floor Heathing

Underfloor heating

Conditions

Due to the slightly heat isolating properties of wood, when applying wooden flooring on an underfloor heating system, built into a screed, additional resistance will be encountered when trying to heat the room.

 

Heat resistance can be reduced by avoiding air pockets and by reducing the total thickness of the floor covering above the heating elements. The floor covering can also be laid loose on condition that the heat resistance of the underlay is limited.

Usually, Rtb ≤ 0.18 m2 K/W is taken as the limit value for heat resistance above the heating elements. For a floor thickness above the heating elements of at least 50 mm (λscreed = 1 W/mK), if one does not take into account the heat resistance of the layers of glue, this means a theoretical recommended thickness of the floor covering (possibly including underlay) of 22 mm for hardwood (λhardwood = 0.17 W/mK) and 15 mm for softwood (λsoftwood = 0.12 W/mK)

 

The maximum water temperature of the heating system is 55 °C. For thermal comfort reasons it is best to ensure that the surface temperature of the floor (which is different from the ambient temperature) does not exceed 28 °C.

 

The relative air humidity at floor surface level must always be between 45 and 65%. In practice this means that a humidifier has to be installed to warranty a minimum humidity !!Always!! this way your floor will keep in perfect condition in summer- and wintertime!.

 

Taking practice into account, it is recommended to use underfloor heating as the basic heating and combine it with convectors for peak or fast heating. It is advisable to use underfloor heating only as the main heating in well-insulated buildings.

 

The installation of underfloor heating must be done by a professional. Input and output must give off the same surface temperatures everywhere. Only your professional installer knows in which places and which insulation thickness to use so that the surface temperature is perfectly equal everywhere. This is extremely important in order to prevent cracks in the surface or deformation of your wooden floor.

 

Multi-layer parquet floors have more stable dimensions compared to solid floors and hence have preference if combined with underfloor heating.

 

It is not recommended to lay carpets on heated parquet floors as this would hamper heat emission from the underfloor heating system even more. In addition, there is a risk that thermal comfort is no longer guaranteed.

 

Installation on underfloor heating:

 

Important: After the screed has been laid, the heating system must only be switched on after the right waiting period, and very slowly (do not use before the screed has dried). It is very important that the instructions are followed up correctly in order to prevent problems with your floor.

 

5 Days before installation the underfloor heating must be switched off or kept at a very low temperature (surface temperature max. 15 °C).

Our floors are suitable for underfloor heating, for which even a thickness up to 21 mm may be used. Hardwood has a very high heat permeability and is highly suitable for this use.

 

For gluing in this case as well, a 2-component PU glue is a must.

 

Start with underfloor heating:

 

Gradually turn on the underfloor heating again three days after installation of the wooden floor covering.

 

The hot water temperature may be increased by 5 °C a day at most, until it reaches 50 °C (not more), with a maximum surface temperature of the screed of 28 °C. This temperature must be maintained for at least 5 days (also in summer).

 

To switch off the underfloor heating, the same values must be respected, or let the hot water temperature cool off 5°C a day at most.