How to determine the moisture level of a concrete screed?
The apartment was leveling the floor with a concrete screed. How long can it wait for it to dry completely? In general, how can you somehow determine the level of moisture screed? It is said that the substrate can prevent moisture from entering the laminate planks. Is it really? Sincerely, Larisa Petrovna.
Hello, Larisa Petrovna! Laminate does not tolerate high humidity, so you should not rush with its laying. The concrete screed has a drying period of one month. After this time, the residual moisture of the concrete is about 2-3.5%.
How can I get an accurate indicator?
Professionals use moisture meters to measure moisture in concrete screeds. Using these high-precision electronic assistants, it is possible to determine the moisture level of the concrete layer within a few seconds. These compact instruments also measure wood moisture. Hydrometers are expensive devices, so it is not advisable to buy them for one-time use. You can rent a moisture meter or carry out instrumental measurements by ordering a service from a specialized company.
An alternative way to measure humidity
It helps to determine the moisture content of the screed and a piece of ordinary plastic film. To use this "grandfather" method, you must:
- cut off a piece in the form of a square from a roll of plastic film, the side of which should be 1 m;
- put the film on the surface of the concrete floor in one of the corners of the room;
- stick all sides of the film to the screed with adhesive tape, ensuring tightness;
- leave the film for a day;
- after 24 hours, see if there is condensation on the inside of the polyethylene.
The presence of water droplets on the film indicates that the screed has not yet dried. It is necessary to extend the time allotted for drying the concrete layer.
Important! This method does not allow to obtain a specific indicator of humidity, therefore, one cannot completely trust its results. Meanwhile, the manufacturers of the laminate indicate the specific moisture level of the base, on which you can install the finish coating.
Will the substrate save?
Special substrates are produced with a polyethylene base that protects the laminate from the action of residual moisture in concrete.
When using ordinary substrates, a plastic film, which serves as a vapor barrier, is sometimes laid on a screed. However, all this is done as a preventive measure a month after laying the leveling screed.
