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
H
hauspeter13 Jun 2020 17:24Lightweight expanded clay aggregate has also been available for over 20 years, since my parents built their house. It always reminded me of pumice stone when you cut it. The advantage back then was that you could skip an external thermal insulation composite system (ETICS) and didn’t have to cover the building envelope with polystyrene. Clay also helps regulate moisture.
All materials have their pros and cons. That’s why monolithic construction is often not the result. Often, good thermal insulation, like with aerated concrete, means poor sound insulation. Or good sound insulation, as with sand-lime brick, usually results in poor thermal insulation. On top of that, there are requirements for moisture regulation and summer heat protection.
I personally chose a cavity wall with 240mm (9.5 inches) Poroton blocks and a ventilated brick veneer façade with insulation. Solid construction on both inside and outside with insulation in between. The wall is almost 50cm (20 inches) thick.
All materials have their pros and cons. That’s why monolithic construction is often not the result. Often, good thermal insulation, like with aerated concrete, means poor sound insulation. Or good sound insulation, as with sand-lime brick, usually results in poor thermal insulation. On top of that, there are requirements for moisture regulation and summer heat protection.
I personally chose a cavity wall with 240mm (9.5 inches) Poroton blocks and a ventilated brick veneer façade with insulation. Solid construction on both inside and outside with insulation in between. The wall is almost 50cm (20 inches) thick.
Well, if I knew that... no one tells you... we asked so many people: architects, structural builders... he even built unfilled himself... our entire street builds unfilled with 36.5 (about 14.4 inches)... everyone you ask thinks what they built is the best they have...
I would say the sound comes in where the weak point is, and in this example, that is the window.
I would say the sound comes in where the weak point is, and in this example, that is the window.
H
hauspeter13 Jun 2020 17:36Snowy36 schrieb:
I would say the sound enters where the weak point is, and in this example, that is the window. Airborne sound insulation only works with mass. The sound stays outside and does not come in. This is well known from solid walls. Airborne sound is only dissipated by porous surfaces where the sound energy is absorbed. This is familiar from recording studios. Impact sound insulation is only achieved through structural separation, such as decoupling pipes or wood ceilings.
It is possible that windows with poor sound insulation are weak points and reduce overall soundproofing. However, the sound insulation of solid walls is certainly not negated as if the entire house were made of glass.
H
hauspeter13 Jun 2020 17:42Tolentino schrieb:
If there are no restrictions regarding money and space, how should one build for maximum soundproofing? 24cm (10 inches) aerated concrete block plus 40cm (16 inches) aerated concrete as thermal insulation? And then sound insulation class 6 windows?If soundproofing is the top priority because you live near an airport or highway, aerated concrete blocks are definitely a good foundation. With an insulated brick wall on the outside. Mixing aerated concrete blocks and aerated concrete for insulation would be unusual.Similar topics