Wooden floors should only be installed on a screed with the appropriate level of moisture. It is assumed that the moisture level of a cement screed should not exceed 2% CM, and the moisture level of anhydrite screed should be less than 0.5% CM. These data refer to substrates without underfloor heating system - if such installation is present in the floor, lower moisture level parameters for the maximum level of screed moisture should be taken into account. For cement screed, this will be 1.8% CM, and for anhydrite screed 0.3% CM.
If the moisture content of the screed is higher than assumed, the focus should be on drying the screed before laying wooden floors. The screed can be left to dry naturally by ventilating the room as often as possible, but this process is very time-consuming and usually takes up to 60 days. An effective, though still relatively lengthy way of drying the screed is through the use of dehumidifiers. These can be used not only to remove moisture from the substrate but also from fresh plaster. By using dehumidifiers, the appropriate moisture level of the screed can be achieved without the need for additional work, but patience is required as this method, although faster than natural drying, still takes time. If time is a constraint, waterproofing membranes are a definitely better (faster) solution.
The operation of a dehumidifier is simple, but for its efficiency, certain conditions must be met. Above all, all windows and doors should be closed. Sometimes it is also necessary to isolate the entire floor with a curtain from the rest of the building. All this is to achieve the lowest possible air humidity, making it easier to "draw out" moisture from the screed or plaster. The dehumidifier works by cooling the water vapor from the room below the dew point temperature, causing it to condense. Dry air (usually at a temperature of 3-8°C higher) is then blown back into the room, and the condensed water is drained into a tank or sewage system.
Using dehumidifiers to reduce the moisture level of the screed is a much more economical and effective method than simply heating and ventilating the room. Furthermore, this method also helps prevent or minimize the risk of surface discoloration and wall cracking, which are characteristic of drying with hot air.
Parkiet Studio offers the rental of modern dehumidifiers that are energy-efficient, while maintaining maximum performance - even at lower temperatures.