Moisture meter for screed

Hello,

our screed has now been heated for 6 weeks. I wanted to lay the tiles soon with my father, but before that I naturally need to check the residual moisture in the screed.

What is the current state of the art? Borrowing a CM device somewhere or are other techniques now reliable as well (impedance, conductivity, ...). I think, for example, Conrad has a device that supposedly can also measure the moisture in the screed and with a tolerance of only +-0.5%, which would be sufficient for me.

Best regards
M.

Hello "bvlgari".
Better leave it with the electrical testing devices; the money would be unnecessarily thrown out the window!
The state of the art for moisture measurement of screeds is still the CM device. You can borrow it, but inexperienced people should also keep their hands off it. There are simply too many sources of error that you need to know in order to exclude them; apart from the systematic error of the measurement method!
With ceramic tiles, just to mention it briefly, you have to proceed particularly carefully. For example, if elastic floor coverings "only" peel off in a wavy manner when the residual moisture was too high, with rigid coverings like tiles and slabs it often leads to a total loss including the screed!! No matter what other sources whisper to you.
NO JOKE
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Regards: KlaRa

How long does a 7 cm thick cement screed (with accelerator) take to dry? Tomorrow it will be exactly 8 weeks since we had the screed installed. Starting from the sixth week, the heating program of the air-water heat pump also runs.

Laymanly, I say, eight weeks, that must work now. Karsten

The drying time of a screed depends on its thickness and the climatic environmental conditions. If regular fresh air supply is not ensured, a cement screed would never reach readiness for laying. Rule of thumb for conventional cement screeds: about 6 weeks for 50mm, about 1 month more for each additional cm of thickness. And this is with optimal climate. From 10cm to 11cm, a cement screed no longer dries voluntarily, meaning on its own and without forced drying! Regards: KlaRa

Does this also apply to retanolestrich? One was laid in our house exactly two weeks ago, and they want to tile next week. It is floating over underfloor heating, which is also running. And all windows always open, good draft, lots of wind, little rain, the screed already looks visually bone dry, very light gray. Karsten