Sound proofing without sacrificing too much space

[PhilM82]

Hi guys. Long-time lurker - hope I'm posting this in the right place. I've recently bought a 1980's semi detached house and have noticed quite a bit of noise coming from next door. My neighbour (single bloke) isn't what I'd describe as a "noisy" person, but I can hear a fair bit of his life through the party wall. It mostly seems to be high-frequency sounds, such as coughing and sneezing and the TV is audible but you can't hear words clearly. I also know when he is washing up! It probably doesn't help that my house is stripped bare for a full DIY refurb so I've very little in the way of furnishings/carpet.

The party wall is (I assume from measuring the space between our windows) 2x 100mm block with a small (<25mm) cavity, with 12.5mm dot and dab plasterboard on each side. While my house is in this state I'm hoping I can do something to help with the sound transmission - as much to insulate him from my noise as me from his.

The problem is the party wall has the stairs on it and the position of the stringer leaves me with under 50mm to play with in terms of adding thickness. The ground floor is totally open plan, with the stairs in the living room.

I'm aware the problem is likely to be caused by flanking, but wondered if there is anything to be gained by adding resilient bars straight to the existing wall and then using 1 layer of soundbloc PB, or just battening the wall and using soundbloc PB.

My joists penetrate the blockwork on my side but I don't know how far though they go - will I benefit from stuffing acoustic insulation under the floor for the first 500mm from the party wall?

Thanks in advance, Phil

 

[jeds]

One layer of soundcheck board - even on resilient bars - won't do much. I've known contractors add two layers in the same situation and the result was negligible. To get good sound attenuation you need a combination of air space, lightweight material and dense material. This disrupts the sound waves and reduces direct transmission. My advice would be remove the existing dot and dab, fix a lining system (e.g. Lafarge Cormet Dryliner Channel) with 25mm acoustic mineral and finished with two layers of either 12.5 or 15mm sound check on resilient bars. When you fix the channel you can adjust the depth to exactly suit the available gap. For maximum sound reduction make the cavity space as large as you can. The mineral should be suspended in the middle of the cavity space.

 

[freddiemercurystwin]

And then report back to say if it was all worth it?

 

[PhilM82]

And then report back to say if it was all worth it?

Yeah, I'm not expecting miracles here