Nowadays, everyone wants to be at home at home. If you live in an older house, this is not always obvious. That is why installing floor heating is a frequently chosen renovation. However, the floors in older houses often consist of a wooden beam construction. These are often not calculated for an additional load of a floor heating system. In this blog I explain what the options are.

There are different types of floor heating on the market. We can classify these into the following two categories:

  1. Traditional wet-type underfloor heating systems
  2. Dry building floor systems

Traditional wet-building underfloor heating systems 


With this system the pipes are laid on the wooden floor plates of the wooden floor beam construction. A layer of 6-7 cm sand cement is then poured over this to get a smooth floor. Because the floor is poured in its entirety, this is called a wet-type underfloor heating system. The major disadvantage of this type of system is the large weight of the sand cement floor. This has an average weight of 125 kilos per square meter. The wooden floor beams of a storey floor are usually not designed for this. If we still want to use this type of floor heating system, we must take measures to reinforce the existing beam construction. There are different solutions for this:

  • Replace complete floor;
  • Add additional support under the floor;
  • Strengthen the existing bars;

o Reinforce beams at the bottom

o Reinforce beams on the side

The first two solutions speak for themselves, but are usually not applicable because they are drastic and cost a lot of money. There is also not always room for an extra support point. A simpler way is to reinforce the existing beams.

Strengthen existing floor beams

A wooden beam with a rectangular cross-section gives its strength and rigidity mainly to the height of the cross-section. It is therefore most effective to reinforce the beams on the bottom and / or top. For this, multiplex plates are used that run at least over the full width of the cross-section and that are also applied over the entire length of the beam. The multiplex plates are glued and fixed to the existing beam with screws, in such a way that the existing beam and the added sheet will behave as a whole.


In some cases it is not possible to reinforce the existing beams on the top an/ or bottom. For example if the ceiling on the bottom cannot be removed. a choice must then be made to reinforce the side beams. Here to, multiplex plates are used which then run at least over full height of the cross-section and are also used over the entire length of the beam. Although it is less effective than reinforcing at the bottom and / or top of the cross-section, it certainly makes sense to apply this method.

Dry construction underfloor heating systems

Drywall underfloor heating systems are systems in which the underfloor heating, instead of in a sand cement floor, is incorporated in an insulation board. A major advantage is that the load is much lower than with traditional wet-building underfloor heating systems. A drywall underfloor heating system weighs approximately 25 kilograms per square meter as opposed to the average 125 kilograms per square meter with a wetwall underfloor heating system. In addition, the construction height is also lower, so that the floor rise is more limited.

There are different systems from different manufacturers on the market. Two of these will be discussed below:

  • Vario pump of the Variotherm brand. With this system the total construction height is 20 mm. This is because an 18 mm fermacell button plate is used between which the heating pipe is pressed. The floor is finished with a special filling compound. This system only weighs 25 kilos per square meter and is therefore very suitable for wooden floor constructions.




Furthermore, a dry-build underfloor heating system has the following advantages over wet-build underfloor heating systems :

  • Faster heat release and distribution.
  • Less risk of cracking in the floor.
  • Floor finishing can be installed faster.

In need of advice ?

Are you planning to use floor heating in your home and are you unsure which floor heating system is best for your situation? Then do not hesitate and contact Studio Flex. We are happy to advise you which system is best for your situation and which measures you should take if necessary.