Screed is the thickest and most water-retentive layer of a floor. Even though its surface may look dry within a few days, it still holds a high level of water inside. When flooring is installed over this water, the water has nowhere to evaporate to; it gets trapped beneath the parquet, dissolves the adhesive, and lifts the flooring.
The rule of thumb known in the industry is that cement-based screed requires approximately one week of drying time per centimeter. A 6 cm screed takes nearly six weeks even under favorable conditions; in an enclosed and humid environment, this period can easily double.
What do we measure?
Measurement is at the heart of screed drying. Touching the surface and declaring it "dry" is not enough; the residual moisture content of the screed must be measured for the flooring to be safely applied. At TeknoDRY, we work with the CM (calcium carbide) method and electronic moisture meters, and we report the result along with date and location information. The flooring contractor can rely on this report with confidence.
- Parquet over cement-based screed: generally below 1.8% CM
- Ceramic tile over cement-based screed: generally below 2.0% CM
- The limit is even lower for underfloor-heated screeds
- The exact value is always based on the threshold set by the flooring manufacturer
How is drying accelerated?
The water inside the screed can only evaporate if it reaches the surface. That's why we manage two things simultaneously: the dryness of the ambient air and air movement at the surface. The dehumidifier draws moisture from the environment, creating a "space" into which the screed's water can be released; air circulators disperse the saturated air layer that accumulates at the surface, sustaining evaporation. When the two work together, the drying time is significantly shortened compared to its natural course.
Keeping the ambient temperature around 20 °C also speeds up the process. In colder months, we provide heater support to keep the screed at the working temperature.
Points to watch out for
Overdoing the drying process is also not correct; if the screed loses water too quickly, cracks may form on the surface. For this reason, the process is carried out in a controlled manner and monitored with measurements. In underfloor heating systems, the heating circuit is activated using the manufacturer's staged program, without applying high temperature directly.
