ᐅ Aerated concrete wall between living room and bedroom is too sound-permeable; which type of double-layer wall should be used instead?

Hello everyone,

We have an 11.5 cm (4.5 inch) Ytong wall between the bedroom and living room, but it’s so thin that you can hear everything from the living room in the bedroom, for example when someone is watching TV at low volume.

Now we are considering adding a second wall in front of the existing one in the living room, with some space between them. One option is a heavy, solid sand-lime brick wall (but in that case, we would need masonry ties between the aerated concrete and the sand-lime brick wall, which means there wouldn’t be a decoupling of the two walls, right?) or a lightweight stud wall with CW/UW metal profiles, mineral wool insulation, and double or even triple layers of gypsum fiberboard.

How would you approach this?

Best regards

I would prefer the stud frame for several reasons:
- much easier to build
- use additional sound insulation
- use decoupled profiles / no contact with the existing wall
- use gypsum-based silentboard for cladding
- possibly a double layer possible

Sand-lime bricks are excellent for sound insulation and, as solid blocks, are very easy for laypersons to bond (time-saving); however, they still require plastering and finishing afterwards.

As an alternative, a stud wall with a minimum CW100 profile, filled with acoustic mineral wool and double-layered with diamond boards, also provides very good sound insulation. Both options are viable, depending on personal preference and taste.

Hello,

why not use a bookshelf (which, of course, will also need to be filled with books). The bookshelf can also have a double back panel filled with mineral wool. Simply placing bricks in front wastes space. In addition, the screed would also need to be removed for that.

Best regards

derdietmar schrieb:

Hello,

why not a bookshelf (which, of course, would then also need to be filled with books). The bookshelf can also have a double back panel filled with mineral wool. Simply placing bricks in front wastes space. Also, the screed would have to be removed for that.

Best regards

You could, of course, also build a bookshelf from drywall... the screed can stay, use ready-made niches and fill them with mineral wool... also a good idea

I would actually recommend sticking soundproofing panels or acoustic panels on the living room wall. That’s the easiest solution, and these panels come in a wide variety of colors, patterns, and designs. Everything else involves a lot more work and mess.

Is the TV placed directly against the wall that borders the bedroom? Or is it even mounted on the wall? Are you only using the TV’s built-in speakers, without any external sound system?
In that case, it might be enough to simply avoid wall-mounting the TV and place it on a stand instead. Or just stick acoustic panels behind the TV...

Honestly, I find it hard to believe, even with an 11.5cm (4.5 inches) thick aerated concrete wall. That has an Rw (sound reduction index) of 39 dB in density class 0.5; my 36.5cm (14 inches) thick exterior walls in density class 0.35 have an Rw of 47 dB. If that were the case, I could never play music loudly in the living room without everyone passing by singing along.

Are you sure the problem isn’t coming from somewhere else? Is the ceiling made of concrete or drywall?
Is the floor construction acoustically decoupled from the wall?