Y-Tong (aerated concrete) - quality building material? (sound insulation!)

Dear forum,

our developer wants to use "Ytong PPW2 d = 36.5 cm on the exterior wall according to the construction specification. Inside 17.5 cm. On the outside, a mineral lightweight plaster of 3 mm is to be applied. That seems a bit "spartan" to me when I see what others install in terms of insulation and stuff.

We wonder whether the requirements for thermal insulation are met without additional insulation? And what about mold and ventilation? A air-to-water heat pump with underfloor heating is planned.

Even greater concerns for us are the noise protection, since we have a cobblestone street in front of the door. A friend who is an engineer told me yesterday that Ytong has "miserable sound insulation properties."

So even triple-glazed windows with enhanced soundproofing probably won’t help? I would ask for honest clarification and possibly alternatives. We have no clue and I don’t want to hear every car! Friends of ours build with sand-lime brick and they are very satisfied. The father is an architect and swears by it.

Many thanks and best regards! If we didn’t have you!

Ytong is very good in terms of thermal insulation, but otherwise just cheap junk. Moisture regulation and indoor climate are also very, very poor. The only advantage of Ytong is that you can easily build your hut yourself. KS is great, but then you have to install an [WDVS] because the stone is not heat insulating. Filled bricks would be another option, but definitely the most expensive.

Well, this is off to a good start. You didn’t write anything about the sound: is it that bad? I heard that there are still different raw densities..

It feels like Ytong has been on the market for a long time. Are the homeowners or DIY builders all that incorrigible? Can anything be done about the moisture issue or for the indoor climate? Or do you mean the sound?

The GU has been building houses for almost 30 years and I actually considered/have considered him competent.. :-/

In another post in the forum, someone wrote the following: "WDVS with lime sand brick/high perforated brick or aerated concrete doesn't differ much in price. It depends on what the shell builder uses more."

Light material like Ytong has very poor sound insulation.

Ytong has remained as a building material because of its extremely good thermal insulation and possibility for self-construction. Very easy to cut and lightweight.

But in the situation you described, it is not the right building material.

The GUs, even the good ones, always recommend what they personally prefer to use. Never what the builder would actually need for their requirements.

The only help is to inform yourself and clearly procure what is desired.

Ytong has less mass and therefore worse sound insulation properties than materials with more mass (e.g. Poroton).