Is ventilation/drying after installing screed/interior plaster sensible?

Since 12/28/16, the interior plaster has been/is being applied until probably the day after tomorrow (roughly calculated, by the way, about 4200 liters of water!). We currently air out 4-5 times daily if the humidity outside is not at 100%. On the ground floor, we heat with a stove, and the plaster dries very well there. On the upper floor, we have had 1 fan and 1 dryer running for a few days. However, the upper floor is drying very slowly. After the screed is applied, we will definitely add a second condensation dryer. The screed is scheduled to arrive in 3 weeks.

We had arranged the following after the screed: 3 days of no ventilation at all, then 2 weeks of shock ventilation (as much as possible), after that to use the help of a drying heater.

Then at some point the heating will be turned on.

Walls and screed should dry slowly.

So you should be on the right track with your thoughts.

Regards

We actually dried with dehumidifiers (this was paid for by our builder because a defect had caused a mold problem). These were set up by a professional company (additionally with fans so that the air circulates properly) and we emptied the dehumidifiers and regularly moved them. According to our expert, the drying also has the advantage that the screed will settle less over time and you may not need to replace the baseboards later (we can confirm this three years later, by the way). Costs of €1,500 for electricity alone were incurred for the drying.

How is the best way to arrange the dryers + fans? Just put the fan somehow into the room so there is some air movement? Or full blast airflow directly on the condenser dryer? Or...?

Should building drying also be carried out at milder temperatures (> 10°) or does it eventually become obsolete?

How do you set up the dryers + fans most effectively? Just put the fan somewhere in the room so there is some air movement? Or full blast airflow directly on the condenser dryer? Or...?

The main point is that small rooms without a dryer have an air exchange with other rooms where a dryer is present. Otherwise, the dryer itself ensures sufficient circulation.

Should construction drying also be done at milder temperatures (> 10°) or does that eventually become obsolete?

I think that’s not the right question. If it’s cold outside, the building is properly heated, and you can air several times a day – then construction dryers are rather obsolete. It actually doesn’t matter how high the outdoor humidity is.

Example: You let cold air with 0 °C and 95% relative humidity into the house and close the windows again. The air warms up to 25 °C and then only has a relative humidity of 18%, so it can absorb a lot more water until a relative humidity of, for example, 75% is reached again. Then you air out again, and the cycle starts over.