Attaching plasterboard directly to breeze blocks

[Peter_ST16]

I'm starting a sound insulation project on my semi. The party wall is breeze block with plasterboard dot and dabbed to it. The spacing between the wall and the plasterboard acts like a speaker membrane amplifying the noise, so I want to get rid of it. I'm going to remove the existing plasterboard, fill in any cavities in the wall and then put two layer of the acoustic plasterboard. Here's the question - can I attach the plasterboard directly to the breeze blocks? E.g. using the adhesive foam? I don't really want add battens as I'm going to lose a lot of space, plus the cost of the acoustic wool. Any suggestions?

 

[23vc]

You can fix it pretty close with foam, yes. There also used to be a plaster called something like thistle sound coat which was applied to the blockwork then the sound bloc boards on top, not sure if it still exists.
Either way, I’d be careful with expectation of how much just board/plaster is going to improve things, lots of threads on here about how/why this needs a lot more (separation of layers, details around floor to wall junctions, proper sound deadening materials) to really work effectively in most situations.

 

[^woody^]

Breeze block? Does that mean the no fines clicker ash blocks from the 1950s? Or concrete or aerated concrete?

And yes, as 23vc says be careful of your expectations. It may be that the person on the other side of the wall benefits most.

 

[Peter_ST16]

Thanks. I'll read a bit more on that.

 

[Deluks]

I don't understand where the acoustic wool will go?
If you are foaming the boards on the wool will just get in the way.

Consider resilient bar with 25mm wool between, the bars are a bit thinner than 25mm though, so you might need to pack out the fixings into the wall. You can squash the wool by a couple of mm but don't over compress it.

This only costs you 25mm of space behind the boards, just a tiny bit more than using foam.