Hello everyone,
I have already read and searched around a bit here, but I am still not quite sure.
We are planning to build a house. It will be a semi-detached house. We have been offered a house with 36.5cm (14 inches) aerated concrete exterior walls without additional insulation. The interior walls are also planned to be made of aerated concrete. Soundproofing boards are to be installed between the wall and the neighboring house.
I have to admit that I am quite a layperson and am slowly working my way through the very conflicting statements and information. We don’t want to build a passive house, but it should be future-proof and reasonably designed. Overall, I would like to aim for a kfw70 house, but that is not solely about insulation...
I have read various information about aerated concrete, clay blocks (Poroton), and also about prefabricated walls. I find it interesting that the U-value of the prefabricated walls is apparently significantly better than that of comparable solid walls (without additional insulation). However, I can’t really grasp what a difference of 0.1 W/(m²K) actually means in reality... I lack the practical understanding of this.
What I think I know:
- Aerated concrete can be installed without additional insulation. But is it any good!? Does it only just meet legal requirements, or is it also sensible to build this way?
- Aerated concrete has poorer sound insulation compared to sand-lime brick or clay blocks. This could be a problem especially for thin interior walls.
- Regardless of what I build (even without extra insulation), a controlled mechanical ventilation system is highly recommended because the houses are very airtight.
- Aerated concrete has poor thermal insulation properties in summer (I still don’t understand why a material supposedly insulates well in one direction – during winter – but not in the other – summer –?!).
- I have often read that the costs of adding extra insulation to a wall do not pay off over a reasonable period (in terms of heating savings – of course this also depends on the heating technology).
Could you help me clarify where I might be wrong? Why is sand-lime brick usually recommended for interior walls instead of aerated concrete? Soundproofing? Less crumbling when drilling? Price?
On the website of the well-known aerated concrete manufacturer, I read that they also achieve low U-values (below 0.2). But these blocks are then less stable, significantly more expensive, and worse in sound insulation... So can you really generalize about aerated concrete or do you need to specify the exact type of block? My supplier only talks about 36.5cm (14 inches) blocks. So I don’t really know which will actually be used... I should probably ask.
Is omitting additional insulation really the “state of the art” and reasonable (does it not pay off in heating costs) or just cheap?
As I said, I don’t want to build a passive house but an economically sensible concept.
Which wall structure would you recommend and why under the above conditions?
Thank you!
I have already read and searched around a bit here, but I am still not quite sure.
We are planning to build a house. It will be a semi-detached house. We have been offered a house with 36.5cm (14 inches) aerated concrete exterior walls without additional insulation. The interior walls are also planned to be made of aerated concrete. Soundproofing boards are to be installed between the wall and the neighboring house.
I have to admit that I am quite a layperson and am slowly working my way through the very conflicting statements and information. We don’t want to build a passive house, but it should be future-proof and reasonably designed. Overall, I would like to aim for a kfw70 house, but that is not solely about insulation...
I have read various information about aerated concrete, clay blocks (Poroton), and also about prefabricated walls. I find it interesting that the U-value of the prefabricated walls is apparently significantly better than that of comparable solid walls (without additional insulation). However, I can’t really grasp what a difference of 0.1 W/(m²K) actually means in reality... I lack the practical understanding of this.
What I think I know:
- Aerated concrete can be installed without additional insulation. But is it any good!? Does it only just meet legal requirements, or is it also sensible to build this way?
- Aerated concrete has poorer sound insulation compared to sand-lime brick or clay blocks. This could be a problem especially for thin interior walls.
- Regardless of what I build (even without extra insulation), a controlled mechanical ventilation system is highly recommended because the houses are very airtight.
- Aerated concrete has poor thermal insulation properties in summer (I still don’t understand why a material supposedly insulates well in one direction – during winter – but not in the other – summer –?!).
- I have often read that the costs of adding extra insulation to a wall do not pay off over a reasonable period (in terms of heating savings – of course this also depends on the heating technology).
Could you help me clarify where I might be wrong? Why is sand-lime brick usually recommended for interior walls instead of aerated concrete? Soundproofing? Less crumbling when drilling? Price?
On the website of the well-known aerated concrete manufacturer, I read that they also achieve low U-values (below 0.2). But these blocks are then less stable, significantly more expensive, and worse in sound insulation... So can you really generalize about aerated concrete or do you need to specify the exact type of block? My supplier only talks about 36.5cm (14 inches) blocks. So I don’t really know which will actually be used... I should probably ask.
Is omitting additional insulation really the “state of the art” and reasonable (does it not pay off in heating costs) or just cheap?
As I said, I don’t want to build a passive house but an economically sensible concept.
Which wall structure would you recommend and why under the above conditions?
Thank you!
H
Hausqualle22 Jul 2015 20:59It is not recommended to use aerated concrete for interior partition walls; instead, calcium silicate blocks should be used.
H
Hausqualle22 Jul 2015 21:04Bautraum2015 schrieb:
I think so too... that's why I asked Very few people truly understand the differences between thermal insulation, thermal conductivity, heat transfer, dew point calculations, and so on, unless they are a building physicist and can perform these calculations... a lot of nonsense is often written...
Bautraum201522 Jul 2015 21:06And what is the difference between the first three you mentioned? I really don't know.
Nobody talks about thermal insulation in summer; it’s about summer heat protection... one factor is the material’s thermal inertia / energy storage capacity. Lightweight building materials like aerated concrete, for example, perform significantly worse with about 80 kJ/m²K compared to a calcium silicate brick with around 300 kJ/m²K. Calcium silicate brick absorbs heat better during the day and can release it again at night (when it is cooler) – acting as a kind of buffer.
Another step is to reduce the heat input – through shading. Other factors include cooling (passive or active).
Transmission heat loss is the heat loss caused by thermal conductivity. The dew point is the location in a wall where condensation may occur – there are good YouTube videos about this... it’s not that complicated.
Another step is to reduce the heat input – through shading. Other factors include cooling (passive or active).
Transmission heat loss is the heat loss caused by thermal conductivity. The dew point is the location in a wall where condensation may occur – there are good YouTube videos about this... it’s not that complicated.
Bautraum201522 Jul 2015 21:20I simply don’t know any better.
Thank you for the explanation!
How does Poroton compare to aerated concrete in terms of summer heat protection? We are planning a 42cm (16.5 inches) wall... but with which material?
Thank you for the explanation!
How does Poroton compare to aerated concrete in terms of summer heat protection? We are planning a 42cm (16.5 inches) wall... but with which material?
H
Hausqualle22 Jul 2015 21:20Bautraum2015 schrieb:
And what is the difference between the first three you mentioned? I really don't know.. .. sorry .. but then I would have to copy entire books ... .. but if you did some browsing on the internet, you would find plenty of literature ... have fun ..Similar topics