How much residual moisture can the tiler start with?

Hello everyone. Our screed still has a residual moisture of 2.6%CM. Exactly 7 days ago it was 2.7%CM. 2 drying units are running continuously... Why is the screed drying so slowly for us? From what %CM can the tiler start his work?

What kind of screed is the question. I mean 3% for cement and about 2% for calcium sulfate. 1.6-2 for laminate/parquet/vinyl

It is cement screed.

Is the underfloor heating already running? Or just the [Bautrockner]?

The screed heating program has already run twice...

It is supposedly only running for 8 days (Viessmann gas heating)

2.0% for cement screed and tiles, 1.8% for parquet. For tiles, there is special adhesive that also works with a higher value. For parquet, you can apply primer beforehand, but that stuff is expensive. 8 days sounds more like functional heating and not drying. Maybe the drying (capillary break) is exaggerated. What temperature do you have, and how humid is it?