Location of city villa or single-family house on 500 m2 plot - rectangular

Well, now the parts delivery crisis has caught me. The heat pump is impossible to get. Although I had pointed this out early and was firmly promised on-time delivery, there was first a delay of two weeks and now even the revision of any delivery date promises by the dealers. The tower is already here and since the additional heater is built into it, there is still hope that it can be used for functional heating. The heating engineer still wants to ask about that at Vaillant. So I would be exchanging expensive electricity bills for further construction delays (which also costs me quite a lot). Meanwhile, the water connection is being finished, the descaling system installed, and everything prepared so that the heat pump only needs to be set up, connected, and switched on. In the meantime, I’m biting my fingernails off.

So, new update: The heating technician installed an all-electric heater for me. So far, the heating program (which runs until Monday) has cost me 2000 kWh. According to Billo hygrometers, the humidity in the house is only 30-50% at around 20°C room temperature. I am currently suspicious whether the screed might have sintered on the surface, as I never had windows fogging up from the inside, let alone actual dripping, which is often reported here. On the other hand, I had three weeks of downtime without heating. Maybe the screed simply had enough time to cure well then? I am curious about the first CM measurement. At the moment, I simply can't get a tiler. My neighbor’s hairdresser has at least agreed, after some consideration, to do the guest bathroom. Maybe he will also do CM measurements at the other measuring points for me. I’m going to try the hardware stores with craft services again now. Drywall installers have also been working since last week, and it looks quite good. The blower door test on Wednesday just passed with 1.5. However, the interior window sills are still missing and the ventilation ducts of the controlled residential ventilation to the outside are not yet finished. That means that if it already passed with these conditions, I hope that the airtightness is quite good. It’s a pity I won’t know the exact value now. Does anyone know how much a blower door test costs? Maybe I’ll just do another one.

I am currently suspicious that the screed might possibly be sintered on the surface, as I never had even windows fogging up from the inside, let alone properly running droplets, which is often reported here. On the other hand, I did have three weeks of downtime without heating. Maybe the screed simply had enough time to cure well during that period?

Why don't you just insert a "Yell 4 expert" = " " in such a question?

I considered it unnecessary at the current time, since I wouldn't lay any kind of floor without a CM measurement anyway. But you have taken that over now. I will also describe the process here in more detail so that can really give a well-founded opinion (if that is possible).

- It is a heated screed based on cement with an average thickness of 7cm
- The screed was treated with the additive Berolith M94
- The screed had a resting time of (checked again - even) 5 weeks before the start of functional heating!
- The manufacturer's protocol for the additive is as follows:
7 days resting time (ACTUAL: 5 weeks)
2 days 35°C flow temperature (complied with)
6 days 45°C flow temperature (ACTUAL: 7 days, due to weekend)
1 day 35°C flow temperature (complied with)
1 day 25°C flow temperature (complied with)
then two days resting or continue heating at minimal level. (currently, flow temperature 23°), the two days would be over on Sunday.

One problem caught my attention right at the beginning: unfortunately, the screed layers left the windows tilted in almost all rooms on the upper floor. As far as I know, all windows should be closed at the beginning, right? Unfortunately, it wasn’t accessible at first, so I couldn’t intervene to reduce that. After the resting time, I ventilated thoroughly in the morning and evening on average (without draft). I have placed very inexpensive hygrometers all over the house. At the beginning, after the screed was allowed to be entered, until about the end of the regular resting time, the average relative humidity in the morning before ventilating was 60-70%, after ventilating 40-50% at about 10-16°C). At the end of the actual resting time (i.e., after 5 weeks) but before the start of functional heating and before ventilating it was about 50-60%, after ventilating 50%. At the beginning of the heating protocol with 35°C flow temperature, the moisture before ventilating shot up to 70-80% at 28°C room temperature (but no condensation), but it dropped quite quickly to about 60%. After ventilating, usually always 30-40% at about 20°C room temperature. From the middle of the phase with 45°C flow temperature (33-34°C room temperature), the pre-ventilation humidity stabilized at about 45%, after ventilating 35% at 28-30°C room temperature. In the last few days, I have not ventilated because the morning humidity remains at 40-50% (21-22°C room temperature) and also the outside humidity is much higher (it is raining almost continuously). Moreover, the drywall installers are already working.

So, dear , based on the above now supplemented described situation, can one be at least 80% certain from a professional point of view that something is wrong because a certain moisture absolutely has to get out, which should have at least settled in the form of slight condensation on the windows? Especially due to the tilted windows at the beginning of the resting time? Or is my assumption, that a correspondingly long resting time can certainly lead to sufficient hydration so that not much moisture forms during functional heating anymore, at least conceivable?

I would be very happy to receive an assessment, even though a CM measurement by a yet to be commissioned professional will of course not be omitted.

Hello "Tolentino".
Your description of the process regarding screed installation and subsequent activities is excellent and quite informative!
The following regarding this:
You did everything right!
With a screed thickness of 70mm, it was indeed sensible to add a plasticizing agent (Berolith M 94) to the screed mortar so that the structure is properly compacted at this installation thickness.
It is also true that the drying time of screeds ALWAYS increases with the thickness.
The surrounding drying conditions, thus the room climate, remain crucial for how quickly a screed dries out depending on its thickness.
That the windows were already "tilted open" during screed installation should not confuse us given the described situation. It ideally should not be this way, so that the screed surface has sufficient water available while hardening (which is a chemical reaction, by the way).
If the window openings had been harmful, it would have ultimately shown in an insufficiently firm screed surface.
But apparently, that is not the case here.
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From the overall contribution, I can only deduce that functional heating was carried out. However, a readiness-for-covering heating is not mentioned.
In any case, please keep in mind that the high moisture, which is always inevitably introduced into the building by installing a wet screed, is also absorbed by the wall plaster etc.!
This means that simply stating a hygrometer reading, assuming sufficient accuracy of indication here, is not really meaningful.
Actually, I cannot see any indication of an existing problem throughout the entire contribution.
If it is suspected that the screed is not yet sufficiently dry to lay a top covering (of any kind) on it, this must be proven by an appropriate measurement or even just a test (which is a huge difference!!).
After screed installation, the screed layer has absolutely no influence on the drying behavior and the required time frame—and is excluded from the chain of responsibilities here, if we can even choose that term at this point.
Do the following to gain sufficient certainty:
Without additional heating, place a PE sheet approx. 1.5m x 1.5m on the screed surface of a room.
Since you reportedly have several hygrometers, "sacrifice" one of them—place it under the PE sheet on the screed and seal the edges of the foil tightly with a well-adhering tape.
Place a second hygrometer next to it, i.e. outside the laid foil, for comparative control purposes. Then open the windows "tilted," even with a slight draft.
After a maximum of 24 hours, compare the readings of both hygrometers.
If the value under the foil is above 75% relative humidity, you should perform a second phase of readiness-for-covering heating for 2 days.
If the value is below that, then all the fuss was for nothing! :)
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Wishing everyone a pleasant weekend: KlaRa

So, a little update from my side. The heat pump is still not here and no delivery date is known. The heating guy had an appointment with a Vaillant representative and got me put on a priority list that is processed according to order date. With an order date in June, I consider myself to have pretty good chances, but who knows... Meanwhile, I have heated the construction with a heat radiator and two infrared panels (basically frost protection mode), since the heating guy needs his direct heating for another construction that has the same problem. With my makeshift devices, I achieve an indoor temperature of 13°C at about 0-5°C outside temperature. I can’t tell if this indicates good insulation, but the consumption is about 80-100 wh per day. :( In the meantime, I had a small walkthrough with the general contractor [GÜ] to roughly see what still needs to be done by his subcontractors and if we could do a handover soon. Basically, the matter is manageable. The electrical box and connections as well as the final installation after my own painting work and the defective base plaster still need to be done. Also, I had negotiated that the too small openings for the controlled residential ventilation in the filigree ceiling, delivered too small, would be repaired. Here, my HVAC fitter had to enlarge the openings. The problem was: 130mm were defined in the planning documents and also delivered. But Vaillant only has 130mm inner diameter pipes that have a 134mm outer diameter. :rolleyes: Sure, my HVAC guy could have asked beforehand if he should simply install 125mm pipes, but by then everything was already ordered. Now I have such ugly break points around the ventilation openings that I would like to have plastered over. I can do it myself or have it done, but if the [GÜ] does it because he admits that this went badly, that would be nice. Furthermore, there was a small spot on the interior plaster around the front door where the plaster was removed too quickly and then bubbles had formed. The [GÜ] tried to say that the painter should rather do that, because calling someone special for that... But since the plasterer has to come again anyway, I did not accept that. Well, during this walkthrough, the [GÜ] then mentioned that the electrician probably won’t have time this year anymore and more or less blamed me because so much had been delayed. That’s true partly, but partly it was not my fault and since he unfortunately mentioned October as a possible timeframe that was also possible for the electrician, I could dismiss that. Because exactly then he could have made it and I had also informed the site manager, who had meanwhile been out sick. Funny detail: The [GÜ] asked me what I would do with the construction stairs once the real stairs are installed. I said I didn’t know yet, maybe put them on a classifieds site. Then he actually expressed interest, but more as a free giveaway. I dryly replied that on classifieds they are sold for 300 EUR. Well, so now acceptance with remaining work carried out so I can finally start with my own work. Electrical work should be done by the end of January, base plaster by the end of April (weather dependent). The final invoice was of course reduced by way too small remaining amounts. I’m curious if anything will really still be done now. But I was just fed up. Want to move forward now, heating or not. The fact is also: no move-in this year. Maybe I have to procure the base plaster myself and then reclaim the costs later, that will be really funny. For electrical work I suspect I have better cards because I haven’t paid the surcharges for the sampling yet. If the electrician wants that, he has to do the remaining work, otherwise I can always say he hasn’t finished. Another problem: I can’t find any tilers who are available now. It’s really crazy.