Hello,
As mentioned in the title, we are building with Ytong to achieve KfW55 standard.
Now our construction company has offered to build with 36.5 cm (14 inches) Ytong blocks instead of 24 cm (9.5 inches) Ytong plus 12 cm (5 inches) of full thermal insulation.
Advantages according to the construction company:
1. All values for KfW55 are met just the same.
2. Fastenings on the exterior wall, e.g. satellite dish, awning, etc., would be much easier to install because it’s solid masonry directly, without soft insulation.
3. Our site manager considers the insulation a sort of "hazardous waste" from his point of view, as its production and disposal are quite energy-intensive...
Disadvantages: none?? Price-wise it would make no difference for us.
What do you think?
Especially point 2 appeals to me...
Point 3 is just a personal opinion and therefore secondary for now.
Thanks and best regards to everyone!
As mentioned in the title, we are building with Ytong to achieve KfW55 standard.
Now our construction company has offered to build with 36.5 cm (14 inches) Ytong blocks instead of 24 cm (9.5 inches) Ytong plus 12 cm (5 inches) of full thermal insulation.
Advantages according to the construction company:
1. All values for KfW55 are met just the same.
2. Fastenings on the exterior wall, e.g. satellite dish, awning, etc., would be much easier to install because it’s solid masonry directly, without soft insulation.
3. Our site manager considers the insulation a sort of "hazardous waste" from his point of view, as its production and disposal are quite energy-intensive...
Disadvantages: none?? Price-wise it would make no difference for us.
What do you think?
Especially point 2 appeals to me...
Point 3 is just a personal opinion and therefore secondary for now.
Thanks and best regards to everyone!
K
Knallkörper7 Mar 2017 15:11astron schrieb:
If I summarize for myself:
Disadvantage: soundI wouldn’t say that. Ytong has better sound insulation properties than the insulation layer of the external thermal insulation composite system (ETICS). However, ETICS has better thermal insulation properties.
36.5cm (14.4 inches) Ytong 0.186 W/m²K
24cm (9.4 inches) Ytong + 12cm (4.7 inches) EPS 0.152 W/m²K
The lower the value, the better, meaning less heat "escapes" through the wall. For KfW55 according to reference values, anything above 0.2 W/m²K would be sufficient. For comparison, my timber frame wall will achieve about 0.11 W/m²K at 39cm (15.4 inches) thickness.
Of course, it also depends on the thermal conductivity class of the materials. I am not sure if there is only one type of Ytong or different variations (regardless of thickness).
24cm (9.4 inches) Ytong + 12cm (4.7 inches) EPS 0.152 W/m²K
The lower the value, the better, meaning less heat "escapes" through the wall. For KfW55 according to reference values, anything above 0.2 W/m²K would be sufficient. For comparison, my timber frame wall will achieve about 0.11 W/m²K at 39cm (15.4 inches) thickness.
Of course, it also depends on the thermal conductivity class of the materials. I am not sure if there is only one type of Ytong or different variations (regardless of thickness).
Yes, aerated concrete is available in different densities.
Styrofoam (polystyrene foam) always provides better thermal insulation than aerated concrete or any other type of masonry, but it is not a masonry material, so it’s an apples-to-oranges comparison.
In my opinion, the main point is that both wall construction options meet the KfW55 standard.
KfW54 or 53, etc., do not exist. From a funding perspective, anything that does not meet KfW40 is considered KfW55.
Meeting only KfW55 already means a good level of thermal insulation. Saving just a few extra dollars on energy costs each month is not worth complicating the wall construction.
I have slept comfortably behind aerated concrete walls and noticed no issues with sound insulation. Even when walking next to metalworking factories housed in aerated concrete buildings, I was not disturbed by noise, although I have good hearing and the environment is certainly not quiet.
If a builder asked me whether I would prefer to plaster masonry or insulation panels, I would choose masonry without hesitation.
.
To summarize:
1) 12 cm (5 inches) of Styrofoam insulates better than 12 cm (5 inches) more aerated concrete.
2) As long as the KfW40 target is not met, it remains KfW55. Whether, theoretically, solid aerated concrete could reach a virtual KfW49, or substituting 12 cm (5 inches) of wall thickness with insulation panels could reach virtual KfW44, is irrelevant for funding.
3) How much of the calculated energy savings from “more insulation” actually translates into cost savings is questionable. I see it as negligible.
4) Aerated concrete is neither a disaster regarding noise and sound insulation, nor can this issue be completely solved by Styrofoam.
5) Solid aerated concrete is dowel-fastening capable on both sides.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Styrofoam (polystyrene foam) always provides better thermal insulation than aerated concrete or any other type of masonry, but it is not a masonry material, so it’s an apples-to-oranges comparison.
In my opinion, the main point is that both wall construction options meet the KfW55 standard.
KfW54 or 53, etc., do not exist. From a funding perspective, anything that does not meet KfW40 is considered KfW55.
Meeting only KfW55 already means a good level of thermal insulation. Saving just a few extra dollars on energy costs each month is not worth complicating the wall construction.
I have slept comfortably behind aerated concrete walls and noticed no issues with sound insulation. Even when walking next to metalworking factories housed in aerated concrete buildings, I was not disturbed by noise, although I have good hearing and the environment is certainly not quiet.
If a builder asked me whether I would prefer to plaster masonry or insulation panels, I would choose masonry without hesitation.
.
To summarize:
1) 12 cm (5 inches) of Styrofoam insulates better than 12 cm (5 inches) more aerated concrete.
2) As long as the KfW40 target is not met, it remains KfW55. Whether, theoretically, solid aerated concrete could reach a virtual KfW49, or substituting 12 cm (5 inches) of wall thickness with insulation panels could reach virtual KfW44, is irrelevant for funding.
3) How much of the calculated energy savings from “more insulation” actually translates into cost savings is questionable. I see it as negligible.
4) Aerated concrete is neither a disaster regarding noise and sound insulation, nor can this issue be completely solved by Styrofoam.
5) Solid aerated concrete is dowel-fastening capable on both sides.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
These are statements I can really work with! Thanks!!
Is the difference between 0.186 W/m²K and 0.152 W/m²K noticeable?
I will also bring these figures up with the site manager… hmm, but for me the biggest argument right now is still the ease of attaching things—satellite dish, sun awnings, etc.
I’m still concerned that we might run into problems if we opt for the insulation.
Sorry for all the beginner questions…
Is the difference between 0.186 W/m²K and 0.152 W/m²K noticeable?
I will also bring these figures up with the site manager… hmm, but for me the biggest argument right now is still the ease of attaching things—satellite dish, sun awnings, etc.
I’m still concerned that we might run into problems if we opt for the insulation.
Sorry for all the beginner questions…
astron schrieb:
I still have concerns that we might run into problems if we decide on the insulation. There are special mounting blocks that can be installed in between for this.
This has also been discussed before in the forum.
astron schrieb:
Is 0.186 W/m²K noticeably different compared to 0.152 W/m²K?Every theorist will strongly say "Yes!!" to that. However, if you prefer traditional window ventilation over living in an air-conditioned environment, the difference won’t really impact your bills. At least, not enough to pay for an extra week of vacation – maybe just three beers or a pack of cigarettes per month. In theory, the difference appears more significant.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
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