Heating of screed ready for covering

Andreas, we ventilated during the warm-up phase. See 1. Beitrag. From NOW ON, we will no longer ventilate.

You could have ventilated a bit before the heating-up phase as well. The moisture needs to get out of the house, otherwise you can wait until the day of judgment...

If you are now drying with a construction dryer, ventilation is indeed no longer effective. When recalculating, it quickly becomes clear that with 3 ventilations per day, you actually don’t get more than 5-10 liters of water out per day.

Two to three construction dryers help significantly more. And turn up the heating! It should get quite cozy in the place.

During the screed drying, we easily consumed 7000 kWh of gas....

But the place was really dry for that.

Best regards,

Andreas

We did air out! From the moment the screed was allowed to be walked on. We followed the instructions completely. We will only stop airing out FROM NOW ON. And there are indeed 2 construction dryers. It's all in my first post - did you read it? And the heating has been running again since today. You can't just switch it from 0 to maximum. What value did you have after 9 weeks then? Just about 1.8 or well below?

Best regards

This here:

- was ventilated properly

is all you write about ventilation. And since I myself have heard three different statements about ventilation from three different people, the significance of your post is very limited....

we only measured once after 6 weeks, then we were just under 2.1% The tiler then already started laying. after 9 weeks someone was supposed to do a CM measurement, but that person canceled. We then relied on the statement of the construction manager, a simple calculation and the humidity measurements: With the amount of screed that was applied in our case, 0.1% corresponds to about 45 liters of water. In the 22 days from the measurement to the laying, we took about 250-300 liters of water out of the air again. The humidity was at most 40% the whole time, sometimes below 30%.

That was enough for us, it fit, there were no problems during laying. Everything bone dry!

The significance of the CM measurement is very limited anyway. For one, it is so error-prone that as an engineer with some understanding of measuring techniques it just made my hair stand on end (the error tolerance is +/- 0.3%...) and on the other hand there are apparently no really established findings about what is considered dry and what is not. There are supposed to be discussions among specialists about raising the limit to 3.0%, others think 2.0% is way too high....

Best regards,

Andreas

Hello.

In general, I would always recommend distributing several hygrometers throughout the house. If the indoor humidity is high, e.g., 80%, then ventilating makes sense at this time of year. Even if it is also 80% humidity outside, water will still be removed due to the temperature difference. Whether there is a dryer in the building at this point is initially irrelevant. Keyword temperature difference: of course, the inside needs to be heated, it should be around 25 °C. Naturally, the screed dries faster the higher its temperature is.

In our case, the screed was ready for covering after 2 weeks, we ventilated 5 times a day (had it ventilated), brand Thermorapid 2.0.

At our place, the screed was ready for covering after 2 weeks, we ventilated 5 times daily (had it ventilated), brand Thermorapid 2.0.

This is a fast screed, certainly 2-3 times as expensive as ordinary cement screed. What did you pay?