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!
@Tego12: Haha, you misunderstood me – I didn’t want to start a debate.
Sound bridges are more often caused by design errors than by the choice of building material. Lightweight doesn’t necessarily mean good vibration damping, since something light can also be stiff...
... the fundamental issue of “thermal bridging” with single-layer construction is not exclusive to any specific material. Autoclaved aerated concrete (AAC) as well as expanded clay combine the stability of solid building materials with long paths for all waves around the little cavities within the structure...
... many of the trendy wall assemblies using insulation boards exceed 40cm (16 inches) in total thickness, so a 36.5cm (14.4 inches) autoclaved aerated concrete wall is comparable.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
Tego12 schrieb:
For me, Ytong is the worst... poor sound insulation
Sound bridges are more often caused by design errors than by the choice of building material. Lightweight doesn’t necessarily mean good vibration damping, since something light can also be stiff...
Tego12 schrieb:
and issues with thermal bridges
... the fundamental issue of “thermal bridging” with single-layer construction is not exclusive to any specific material. Autoclaved aerated concrete (AAC) as well as expanded clay combine the stability of solid building materials with long paths for all waves around the little cavities within the structure...
Tego12 schrieb:
Also, unnecessarily thick walls with proper thermal insulation.
... many of the trendy wall assemblies using insulation boards exceed 40cm (16 inches) in total thickness, so a 36.5cm (14.4 inches) autoclaved aerated concrete wall is comparable.
https://www.instagram.com/11antgmxde/
https://www.linkedin.com/company/bauen-jetzt/
11ant schrieb:
@Tego12: Haha, you misunderstood me – I wasn’t trying to start a debate Okay, let’s say I understood correctly and still answered
11ant schrieb:
Sound bridges occur more from design flaws than from the choice of building materials. Lightweight doesn’t necessarily mean good vibration damping, because lightweight can also be stiff...True. But you can’t really draw a conclusion from that argument. Without design errors, a Ytong wall has one of the worst sound insulation values among all possible wall constructions.
However, I think we agree on this: Much more important than the actual wall construction is that the company knows the wall system well and builds properly.
11ant schrieb:
... the basic “thermal bridge” of a single-layer wall is not a characteristic of any specific material. Aerated concrete as well as expanded clay combine the stability of solid materials with long paths for all thermal waves around the cavities in their structure...I was only referring to the comparison between an External Thermal Insulation Composite System (ETICS) wall and a monolithic wall. Naturally, monolithic walls have more thermal bridges. I hardly know of any objective studies here, except the Fraunhofer ones, which conclude that monolithic buildings more often have facade damage than ETICS buildings (which I find interesting since it contradicts the fairly widespread opinion that ETICS facades are all prone to damage by woodpeckers).
11ant schrieb:
... many of the trendy wall constructions with insulation panels exceed a total thickness of 40cm (16 inches), where a 36.5cm (14.4 inches) aerated concrete wall is on par.Of course, I can make any wall “as thick as I want,” but the discussion was about the insulation performance. With the same wall thickness, you can achieve significantly better insulation using ETICS.
I also have a considerably thicker wall construction myself, but that’s simply because we’re building a cavity wall. If we had built a single-layer wall, Ytong would have been my last choice, even though it would have been the cheapest option here. But then again, that leads us back to the debate.
B
Bieber08152 Mar 2017 07:58It would be interesting to hear from @astron again.
S
Schischka5 Mar 2017 23:49The site manager is absolutely right. We built our house monolithically using Poroton T8 blocks, 43.5 cm (17 inches) thick, filled with perlite. Inside, we added a 5 cm (2 inch) layer of Ytong for installation space to run all kinds of cables and pipes. The house has two full stories plus a pitched roof. However, the gable ends of the attic were built with 25 cm (10 inch) Ytong blocks. For the current attic conversion into a playroom, we glued 80 mm (3 inch) WEDI boards onto the gable walls (using tile adhesive from Toom for about €4.19 per bag). The rafters insulated with 200 mm (8 inch) Rockwool were covered with drywall.
The soundproofing is the best in the entire house (except for the basement, which is made of 30 cm (12 inch) waterproof concrete).
The weak points are always the transitions, such as from wall to window or door.
If these are not properly foamed and finished with the appropriate membrane or if the plaster does not overlap correctly, the sound insulation is effectively zero.
Also, the old built-in roller shutter boxes in the masonry are outdated for monolithic construction. Exterior roller shutter boxes with electric drives should be used instead.
If all these factors are taken into account, the house could even be built from papier-mâché and still be soundproof.
Of course, mass, density, and multilayer construction are beneficial, but there are alternative methods as well.
The soundproofing is the best in the entire house (except for the basement, which is made of 30 cm (12 inch) waterproof concrete).
The weak points are always the transitions, such as from wall to window or door.
If these are not properly foamed and finished with the appropriate membrane or if the plaster does not overlap correctly, the sound insulation is effectively zero.
Also, the old built-in roller shutter boxes in the masonry are outdated for monolithic construction. Exterior roller shutter boxes with electric drives should be used instead.
If all these factors are taken into account, the house could even be built from papier-mâché and still be soundproof.
Of course, mass, density, and multilayer construction are beneficial, but there are alternative methods as well.
S
Schischka6 Mar 2017 00:24Regarding mold. Mold does not develop because of walls that are too airtight, but rather due to homeowners who are stingy with heating and ventilate incorrectly, or because of poor workmanship and thermal bridges—nothing to do with heat.
Example.
Cold air continuously flows in under a poorly installed windowsill and meets warm air inside. Warm air cools down and releases its moisture, as cold air cannot hold as much moisture as warm air—this results in condensation. Simple physics.
The same happens with tilt ventilation and also with drafty shutter boxes.
All of this plus wallpaper, drywall, wood, or similar materials = perfect conditions for mold.
Water, nutrients, and room temperature—what else does mold need to thrive? Water is the most important—no water, no life. Our house is mold-free, but the neighboring brick house is not. The highly praised glass wool insulation in the air cavity absorbs water and transfers it to the calcium silicate masonry. There are whole puddles behind the brick façade trapped by the vapor barrier membrane. I still don’t understand why it’s installed. When the neighbor opened the masonry sealed by the praised membranes, a real cloud of vapor came out.
It also makes no energetic sense to install exterior thermal insulation and then heat the entire masonry— but that’s a different issue.
A controlled mechanical ventilation system with heat recovery already removes condensation from the air in the heat exchanger and supplies dry air to the room. Always fresh air and no condensation.
Nevertheless, I still perform regular shock ventilation daily.
Example.
Cold air continuously flows in under a poorly installed windowsill and meets warm air inside. Warm air cools down and releases its moisture, as cold air cannot hold as much moisture as warm air—this results in condensation. Simple physics.
The same happens with tilt ventilation and also with drafty shutter boxes.
All of this plus wallpaper, drywall, wood, or similar materials = perfect conditions for mold.
Water, nutrients, and room temperature—what else does mold need to thrive? Water is the most important—no water, no life. Our house is mold-free, but the neighboring brick house is not. The highly praised glass wool insulation in the air cavity absorbs water and transfers it to the calcium silicate masonry. There are whole puddles behind the brick façade trapped by the vapor barrier membrane. I still don’t understand why it’s installed. When the neighbor opened the masonry sealed by the praised membranes, a real cloud of vapor came out.
It also makes no energetic sense to install exterior thermal insulation and then heat the entire masonry— but that’s a different issue.
A controlled mechanical ventilation system with heat recovery already removes condensation from the air in the heat exchanger and supplies dry air to the room. Always fresh air and no condensation.
Nevertheless, I still perform regular shock ventilation daily.
Schischka schrieb:
Cold bridges, no heat. That alone disqualifies any building physics statements in your post.
There is no cold, only heat or a lack of heat. Accordingly, there are only thermal bridges.
Schischka schrieb:
If you pay attention to all these things, the house can be built even from papier-mâché and still be soundproof. That shows true expertise – but none in building physics.
Similar topics