Underfloor heating in a new screed

In a renovation we can help you with the entire process. With more than 20 years of experience in wooden floors on underfloor heating, we have a lot of knowledge in house. For example, we can install the underfloor heating and pour a new sand-cement screed over it. We can take care of the removal of the existing floor for you. We also offer the installation of underfloor heating in a new screed as a separate service.

Construction of sand cement screed with underfloor heating

At Uipkes it is possible to pour a new sand cement screed with underfloor heating. Over the years, Uipkes has gained experience in providing a new screed floor in collaboration with renowned parties. A new screed is made if the old (often wooden) screed is no longer good and safe to provide a certain strength in the construction, or if an extension is being built. This can also be chosen if the beams layer is no longer suitable.

With the work we assume that the foundation has been prepared. Floor insulation plates (tacker plates) are placed on the foundation to prevent heat loss from the pipes downwards. A metal grid is placed on the plates to which the pipes of the underfloor heating with a thickness of 16 mm are attached. The pipes are connected to the distribution station. The pipes are placed in a hairpin or snail shell shape. The hairpin shape is often used in rooms with large windows, because the pipes can then be placed close to the window frame. With main heating, a distance of 10 or 12.5 cm from center to center is desirable.

Once the pipes have been installed, they can be connected to the distribution station, which can be linked to the boiler supply and discharge. A sand-cement screed is poured over the pipes on the metal grid.

The sand cement screed must comply with a D20 standard. This is important so that the skin tensile strength is high enough for the new wooden floor, so that it does not pull the sand-cement floor off due to the working of wood. It is important that the sand-cement screed is lubricated with a flatness class 2. This means that the floor may have a slope of 4 mm over a distance of 2 meters. The floor does not have to be level, but it does have to be flat. The minimum height required between the pipes and the top of the sand-cement screed is 30mm. This is necessary to get a minimum flat distribution of the heat to the surface.

The sand cement screed must dry for at least 28 days before the underfloor heating can be switched on. If the drying time is unclear, you can use an average of approximately 1 week of drying time per applied height of 1 cm. So with 5 cm screed, approximately 5 weeks of drying time should be observed. During the drying period, the screed can be walked on, but it is not yet strong enough for mechanical stress.

Speed up drying time??

There are options to speed up the drying time. This can be achieved by applying a drying accelerator, such as DURAMIT, in the sand-cement screed before it is poured. The drying time accelerator strengthens the mechanical properties of the sand-cement screed and can reduce the drying time described above by half. In many cases, heating up the floor can be started after 10-14 days.

On the other hand, a drying time accelerator requires an extra investment compared to the sand-cement floor in which a drying time accelerator has not been incorporated.

What should happen after the drying process?

After the drying period, the underfloor heating may be switched on and it is important that the start-up protocol is followed. By going through the start-up protocol, the screed will 'settle' and ensure that the sand-cement screed shows an effect; it will expand and contract, something which is important that it is done before the wooden floor can be installed, because you do not want this effect to react to the new wooden floor. An additional advantage of going through the start-up protocol is that any residual moisture that may still be in the sand-cement screed evaporates.

The heating protocol takes about 10-14 days. This is started at 20 - 25 degrees water temperature. The water temperature is increased by 5 degrees per day. Continue this until the maximum water temperature of the system is reached. You leave the system at the maximum temperature for a few days. The number of days corresponds to the thickness of the sand-cement screed, at 5 cm thickness you keep 5 days for the maximum temperature.

After going through the start-up protocol, the moisture measurement can take place. When the moisture measurement is below 1.5%, the sand-cement screed is ready to install the wooden floor.

Cost of new screed with underfloor heating

For the cost indication we assume an area of ​​50m2.

  • For pouring a sand-cement screed with finish, you have to take into account a cost forecast from € 30,-/m2 incl VAT. The application of a drying time accelerator costs approx. € 30-/m2 incl VAT.
  • The investment for placing the underfloor heating on a grid, placing the pipes, placing the distribution station and connecting the pipes to the distribution station amounts to an investment of approximately €2500 for a space of 50m2. ,- including VAT.
  • Installing the wooden floor depends on the pattern, which varies from €126 to €250.

Doorloop tijd van een nieuwe dekvloer

Based on approximately 50 square meters, the following lead time can be adhered to:

  • It takes approximately 6-8 weeks to pour the sand-cement screed without drying accelerator until the wooden floor is installed.
  • It depends on the thickness of the screed. Installing the insulation, grid and pipes takes approximately 1 day.
  • Pouring the floor takes 1 day, after which the floor has to dry. After 28 days, the heating protocol of 10-14 days can be started.
  • When the floor is dry enough, we can install the wooden floor. This can take approximately 3 days into account. After 3 days, the floor should dry for 2 days.

Aandachtspunten

  • Sand-cement screed must comply with D20 standard with regard to skin tensile strength
  • The sand-cement screed must comply with flatness class 2.
  • Residual moisture percentage of maximum in combination with underfloor heating 1.8%
  • Drying time of at least 28 days before the underfloor heating can be turned on
  • 1 week drying time per 1 cm layer thickness screed
  • With drying time accelerator, the drying time can be halved
  • At the position of the distribution station, a supply and discharge of the heating boiler must be prepared.
  • There should also be a power point at this location.
  • If necessary, Uipkes Wood Flooring can provide a plumber who will take care of preparatory work.

Have a new screed with underfloor heating installed?

Do you have a project where a new screed with underfloor heating needs to be installed? We also offer the installation of underfloor heating in a new screed as a separate service, without purchasing a new wooden floor from Uipkes. Visit one of our showrooms in Alphen, Amsterdam or Naarden and discuss the possibilities!

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