Wet underfloor heating system and wooden floors

A wet construction underfloor heating system is the most traditional underfloor heating system. This underfloor heating system includes all types of underfloor heating that are installed on shrink nets, (preformed) studded plates or tacker plates. The pipes are secured to create the right firmness and stability of the floor. This is because the screed floor will expand or contract under the influence of the temperature that will pass through the pipes.

A finishing floor is poured over the pipes, such as a sand-cement screed, anhydrite screed, wood magnesite or a leveling compound, which completely covers the heating pipes. With this method of finishing, the drying times specified for the various poured screeds must be taken into account.

A wet construction underfloor heating system has a longer heating time, but on the other hand, the screed is heated evenly and the heat is retained for longer.

Wooden herringbone floor installed on underfloor heating in a beautiful villa in Rotterdam

Applications

The wet-construction underfloor heating system with a fixed screed is often used in new-build homes and apartments or in the renovation/conversion of an existing home where the screed has to be renewed.

This system is often used in new apartments in combination with a floating floor, which also allows noise reduction to be achieved.

Wet underfloor heating system for wooden floor

How does it work?

This is a pipe system with hot water supply and drainage. When installing on shrink nets or tacker plates (from the foundation), the coverage of the finishing layer above the underfloor heating pipe must be at least 3 cm in connection with strength and heat distribution in the floor. The concrete, anhydrite or wood magnesite screed can be applied directly to the construction floor (a fixed screed). A thermal and vapor barrier insulation must then be applied to the underside of the construction floor.

In new apartments or on floors, this heating system is often used in combination with a floating screed.
The screed is then not fixed to the construction floor. A thermal-acoustic insulation layer of sufficient hardness is applied between the construction floor and the screed floor. This layer retains moisture and prevents heat loss to the foundation and crawl space. A noise reduction is also achieved in apartments and floors.

With an installation on (preformed) studded plates, the pipes are higher on the surface. The screed often consists of a leveling material. The 'wet' layer surrounds the pipes of the system, so that both heat and cooling are properly transferred to the screed. The distance between the top of the screed and the pipes must be at least 3 mm. An example of this system is warpsystems/VAriotherm. It is important that the pipes are completely covered. This type of material sometimes shrinks during the drying process and sometimes the pipes become exposed. An additional leveling layer must then be applied.

The heating pipes are connected to the distribution station, which is connected to one of the control systems. The distribution station ensures the passage of hot water through the pipes in the floor. At the distribution station you can often set the temperature of the water that goes through the pipes, so that water is never too hot.

Herringbone floor installed on wet underfloor heating system

Wet construction underfloor heating system in combination with wooden floors

A wet construction underfloor heating system works well in combination with a wooden floor. We glue the wooden floor directly to the screed for ideal heat transfer. In addition, wood is naturally a "warmer" floor, which gives a pleasant feeling even without the underfloor heating.

Points of Attention

  • Pipe depth determines the maximum flow temperature of the water
  • Drying time of the type of screed must be observed. This can affect the schedule
  • Longer heating time of the underfloor heating