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

There are Ytong blocks with an increased sound insulation value. Ask the building materials dealer or developer you trust. Alternatively, there are also aerated concrete manufacturers who offer a combined block: Outside 125 mm aerated concrete Middle 100 mm rigid foam core insulation Inside 175 mm aerated concrete This in one block.

Just spoke with Ytong. It was a professional consultation. The recommendation was (without knowing the situation on site exactly, so with reservation) still a Ytong 36.5 PP2 0.35 / 0.009. I was told that especially the windows must be very well soundproofed, because otherwise even the best limestone sand brick wall won’t help – especially in a two-story city villa with large window areas.

In addition, with limestone sand brick there is a high risk that the thermal insulation composite system (WDVS) will increase the noise again, and you won’t really benefit from the limestone sand brick. Therefore, we should stick to the 36.5 Ytong, choose good soundproof windows, and especially consider a Ytong solid roof, because it is often overlooked how noisy a wooden construction roof can be.

A facing construction made of wood or similar on the house wall facing the paved street is also conceivable, according to the advisor.

We will measure the sound levels over the weekend and see. Ytong also recommended this to us, because only the real environmental values provide information about the required soundproofing.

What I have learned so far: Unfortunately, sound protection and thermal insulation do not go together.

Outside 125 mm aerated concrete
Middle 100 mm rigid foam core insulation
Inside 175 mm aerated concrete. This all in one block.

And here the sound is significantly better then?

There are Ytong blocks with an increased sound insulation value. Ask the building materials dealer or developer you trust.

Alternatively, there are also aerated concrete manufacturers who offer a combined block:
Outside 125 mm aerated concrete
Middle 100 mm rigid foam core insulation
Inside 175 mm aerated concrete

This all in one block.

Although that sounds more like an improvement in insulation rather than soundproofing…?

Just spoke with Ytong on the phone. It was a professional consultation. The recommendation was (without knowing the situation on site exactly, therefore subject to reservation) still a Ytong 36.5 PP2 0.35 / 0.009.[…]

So Ytong recommends Ytong?

I can only agree with the tenor of the previous speakers. Monolithic wall construction with Ytong and good sound insulation is not possible. With an RDK of 0.6 for exterior masonry, this is not surprising either. Physics is physics, even Ytong cannot argue that away. The R´w,R with Ytong is limited to 49 dB.

Then a warm welcome Kalksandstein - the developer is currently revising the offer. Are there any recommendations for the construction of a monolithic exterior wall with Kalksandstein - thickness of the stones, thickness of the [WDVS]?!

Monolithic and sand-lime brick are practically mutually exclusive, that would be very expensive and you would have really thick walls. The thickness of the ETICS results from the energy saving ordinance calculation. We have a 175 mm thick sand-lime brick for the exterior masonry and inside for non-load-bearing walls 115 mm or also 175 mm. This results from the structural calculation. Regarding sound insulation, you can also choose a brick with high bulk density for the sand-lime brick, then you have more mass (and better sound insulation). Have you ever thought about having the house clad with facing bricks? Then you would have a really good wall structure in combination with sand-lime brick.