Hello dear community,
Although this topic has been discussed in several posts before, long-term experiences are missing here.
I am currently planning a 150 m² (1,615 sq ft) new build with a basement. We have now narrowed down our choice to two builders who differ fundamentally in their building materials.
The house is planned to be built without insulation, using a monolithic construction method. One builder wants to use aerated concrete or Poroton blocks (wall thickness 36.5 cm (14 inches)), while the other plans to use a solid precast wall made of expanded clay aggregate with a wall thickness of 41 cm (16 inches). We are now a bit uncertain because the thermal transmittance (U-value) given by the builders differs greatly: 0.21 W/m²K for Poroton and 2.2 W/m²K for expanded clay. Both assure us that the houses meet the KFW 55 standard.
I am unclear how the U-values can differ so much or whether other factors, such as the mortar used with Poroton, are included. The insulation in the attic and the windows (triple glazed) seem comparable in both cases. Are there any long-term experiences in this forum with solid walls made from expanded clay?
Can you tell me whether a similar energy balance for heating can be expected based on the KFW 55 standard?
Our concern is that with poor insulation and a heat pump, we might not achieve sufficient room heating or end up with very high heating costs due to additional electric heating rods.
Best regards,
Sven
Although this topic has been discussed in several posts before, long-term experiences are missing here.
I am currently planning a 150 m² (1,615 sq ft) new build with a basement. We have now narrowed down our choice to two builders who differ fundamentally in their building materials.
The house is planned to be built without insulation, using a monolithic construction method. One builder wants to use aerated concrete or Poroton blocks (wall thickness 36.5 cm (14 inches)), while the other plans to use a solid precast wall made of expanded clay aggregate with a wall thickness of 41 cm (16 inches). We are now a bit uncertain because the thermal transmittance (U-value) given by the builders differs greatly: 0.21 W/m²K for Poroton and 2.2 W/m²K for expanded clay. Both assure us that the houses meet the KFW 55 standard.
I am unclear how the U-values can differ so much or whether other factors, such as the mortar used with Poroton, are included. The insulation in the attic and the windows (triple glazed) seem comparable in both cases. Are there any long-term experiences in this forum with solid walls made from expanded clay?
Can you tell me whether a similar energy balance for heating can be expected based on the KFW 55 standard?
Our concern is that with poor insulation and a heat pump, we might not achieve sufficient room heating or end up with very high heating costs due to additional electric heating rods.
Best regards,
Sven
E
Einradbrot27 May 2020 23:31I recommend Ytong. It does have some issues with sound insulation, but nothing that can’t be solved. Ytong is simply solid. I also looked into lightweight expanded clay aggregate (LECA) with Lechner solid construction houses, but this material is highly prone to many unsightly cracks in the masonry.
nordanney schrieb:
Well, your question should be: Do you have windows? Soundproof windows initially have nothing to do with the wall construction.Why is that? I also think that normally the windows are the weak point when comparing sound insulation of wall assemblies... a standard window provides about 32 dB, a soundproof window with different glass about 42 dB... so if you have regular windows and a wall that provides 40 dB, sound will pass through the window...H
Herr Stein12 Jun 2020 11:27We have a 36.5cm (14½ inch) Poroton wall (Wienerberger T10, unfilled). The interior is already plastered, the exterior is not yet. So far, I don’t feel it is very soundproof. Conversations can be heard clearly outside the house, and singing even easily from across the street. I wouldn’t attribute this to the windows (triple-glazed) or the front door (heavier aluminum version)...
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