ᐅ Y-Tong (aerated concrete) – a quality building material? (Sound insulation!)

Dear Forum,

Our developer plans to use "Ytong PPW2 d = 36.5 cm (14.4 inches) for the exterior walls according to the scope of work. Inside, 17.5 cm (6.9 inches). On the outside, a 3 mm (0.1 inch) mineral-based lightweight plaster will be applied. To me, this seems somewhat minimal compared to the insulation and materials others are using.

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

What worries us even more is the soundproofing, since we have a cobblestone street right outside. A friend who is an engineer told me yesterday that Ytong has "poor sound insulation properties."

So even triple-glazed windows with enhanced soundproofing probably won’t help much? [B] I would appreciate honest clarification and possibly some alternative suggestions. We are not experts and I don’t want to hear every car! Some friends of ours build with calcium silicate blocks and are very satisfied. Their father is an architect and swears by them.

Many thanks and best regards! We would be lost without you!

Ytong provides very good thermal insulation, but otherwise it is low-quality and cheap. Its moisture regulation and indoor climate performance are also very poor.

The only advantage of Ytong is that you can easily build your house yourself.

Calcium silicate bricks are excellent, but you need to install an external thermal insulation composite system (ETICS) because the bricks themselves are not insulating.

Insulated bricks are another option, but definitely the most expensive.

Well, this is off to a good start. You didn’t mention anything about sound insulation: is it really that poor? I’ve heard that there are different densities available.

It feels like Ytong has been on the market for quite a while. Are homeowners or self-builders really that uninformed? Is there anything that can be done about moisture issues or to improve indoor climate? Or were you referring to sound insulation?

The general contractor has been building houses for almost 30 years, and I actually considered him competent... :-/

In another post in the forum, someone wrote the following: "ETICS with sand-lime brick/hollow brick or autoclaved aerated concrete is similarly priced. It depends on what the shell builder installs more of."

Lightweight material like Ytong provides very poor sound insulation.

Ytong has remained popular as a building material due to its excellent thermal insulation and suitability for self-construction. It is very easy to cut and lightweight.

However, it is not the right building material for the location you described.

General contractors, even the good ones, always recommend what they personally prefer to use, never what the client actually needs for their requirements.

The only solution is to inform yourself and clearly specify what you want.

Ytong has less mass and therefore provides poorer sound insulation compared to materials with greater mass (e.g., Poroton).