Building a party wall that will be as soundproof as possible

[DIYedboy]

My connected neighbour and I will be jointly extending the back of our 1930's semi's. It makes sense to build our party wall to be as soundproof as possible, but which is the best solution, cavity, aircrete blocks, solid wall, concrete blocks???

 

[Beefpotnoodle]

I have an issue with a noisy neighbour, the research I've done suggests a mutli-layered wall. Sound is a vibration so with different materials, different frequencies are blocked. Such as triple glazing, the air space and thickness of glass is altered through the unit.
I don't know what you've got to work with, but sound travels down joists etc. And consider db plasterboard.
All the best

 

[DIYedboy]

Thanks BPN,my neighbours aren't noisy, but if we are building the wall it makes sense that the construction method we choose is the best at reducing sound.

So should we build a cavity or a solid? should it be aircrete or concrete block?

 

[Beefpotnoodle]

I have no experience of building a wall with sound proofing in mind. I've got solid brick and I can see why isn't not the best for sound proofing based on what I've seen. I'd lean towards cavity. And again as long as there is insulation, and two skins of different brick that's a good start!

 

[^woody^]

7N dense concrete blocks and an air cavity, with any joists on hangers.

Rockwool slabs in the cavity and no air may or may not help, but you'd need to get that worked out to see if there is any benefit, or a detriment.

And a separation joint between the party wall and external wall, but your designer should really know that - along with the connection to the existing house wall