sound transmission in interior walls, insulation or not

[TorOdd]

Wondering a bit about interior walls. In our planned house, there are chipboard and gypsum in the interior walls but no insulation as standard. The seller claims that the double boards provide as good sound insulation as gypsum + insulation. Is there anyone out there in the house-building jungle who has experiences and/or opinions on this to share?

 

[gadu^]

We have a similar construction at home. We are remodeling the kitchen now and are taking the opportunity to install mineral wool and double plasterboard, and seal joints with latex caulk.
It was a huge difference compared to the other walls where the interior is empty.

 

[anaitis]

Mineral wool provides almost no sound insulation at all. The best way is plasterboard, preferably double, + sealing of joints and gaps.

If you want to achieve really good sound insulation, you should use separate frames for the two sides of the wall + double plasterboard.

 

[Elvis69]

Wondering a bit about inner walls. In our planned house, it's chipboard and plaster in the inner walls but no insulation as standard. The seller claims that the dual boards provide as good sound insulation as plaster+insulation. Is there anyone out there in the house-building jungle who has experiences or opinions on this that they can share?

The seller you talked to is rambling a bit in my opinion.

The wall you describe above, but with 2 layers of plaster on each side, provides about 40 dB reduction if you have a 70 mm frame or larger. If you replace the two inner layers with, for example, OSB, the reduction decreases by about 3 dB, which is a barely noticeable difference. Link

However, if you compare an uninsulated wall with an insulated one, it differs by 8 dB which is a bit more. It is usually said that 8-10 dB is perceived as a doubling.

Then I agree with Anaitis that the connections are very important. However, I would fill that wall with insulation for an optimal result.

 

[bergstrollet]

When you seal the joints with latex sealant... do you seal the OSB/particle board or do you seal the gaps only after the drywall is installed?

 

[gadu^]

When you seal the joints with latex sealing... do you seal the OSB/chipboard or do you only seal the gaps once the plasterboard is in place?

I didn't use OSB+plasterboard but double plasterboard. I sealed all the joints in the first layer, then applied the second layer of plasterboard overlapping and sealed the joints.

 

[Elvis69]

I didn't use OSB + plasterboard, but double plasterboard. I sealed all the joints in the first layer and then applied the second layer of plasterboard overlap and sealed the joints.

It's sufficient to seal the first layer along connecting walls, floor & ceiling. Sealing every joint is overkill provided it's screwed properly. If you then place the next layer overlapped as described above, you're all set

 

[gadu^]

It is enough to seal the first layer along the connecting walls, floor & ceiling. Sealing every joint is overkill provided it is screwed properly. If you then place the next layer overlapped as described above, job done

Might as well do it right from the start...

 

[bergstrollet]

The reason I asked is that OSB should be set with a 2 mm gap (for board movement).

It will be a lot to seal if all these gaps need to be grouted... That's why I wondered if it's better to seal when the drywall is installed (along the ceiling, floor, and adjoining walls).