Reducing sound through party wall in loft conversion?

[Ian H]

Ok cheers, i've knocked up a diagram in AutoCAD:

 

[HERTS P&D]

Shouldn't the word 'Stud' be pointing to the person?

Andy

 

[Paintguy]

I used a very similar approach to that shown in your highly detailed technical drawing

Skip the background if you like but when we moved into our house the neighbours seemed like a perfectly respectable couple, but we soon found out that they fought like cat and dog. Screaming/shouting/swearing at each other almost constantly, often late at night. We were on the verge of moving back out but couldn't face the upheaval so soon after moving in. We had to do something though, not least as we didn't want our young son growing up next to the kind of language they used!

I lined the whole party wall with 30mm high density rockwool slabs, held in place by adhesive and insulation fixings. I left a small air gap for isolation then built a stud wall with minimum contact points to the fabric of the house (none to the party wall itself). The space between the studs was filled with regular rockwool bats, then covered with 2 layers of plasterboard, with staggered joints, sealing any joints, gaps or edges thoroughly on both layers.

Sure we lost a good few inches of living space and I had to narrow a couple of doorways, but the reduction in sound transfer was dramatic. From sounding like they were in the room with us to a point where we could barely hear anything, only the slamming of doors.

They have since moved out, and we hardly ever hear anything from our new neighbours. Even the occasional party that we can hear when outside in the street is virtually inaudible inside the house.

 

[^woody^]

The diet seems to be working, so well done for that, but I'd get someone else in to do the studwork.

 

[pilsbury]

Ok cheers, i've knocked up a diagram in AutoCAD:

View attachment 134991

What is “plasterboann”? I’d be inclined to use plasterboard or something similar.

And similar to your last drawing effort, avoid smoke in the cavity. No sound insulating properties

 

[endecotp]

avoid smoke in the cavity. No sound insulating properties

And snakes. Also not ideal in a cavity.

 

[Ian H]

I lined the whole party wall with 30mm high density rockwool slabs, held in place by adhesive and insulation fixings.



I left a small air gap for isolation then built a stud wall with minimum contact points to the fabric of the house (none to the party wall itself). The space between the studs was filled with regular rockwool bats, then covered with 2 layers of plasterboard, with staggered joints, sealing any joints, gaps or edges thoroughly on both layers.

That sounds great, except for your noisy neighbours, ours aren't noisy but I thought while the wall is bare I may as well add some soundproofing.

Do you remember the exact 30mm stuff you used?

 

[Paintguy]

Do you remember the exact 30mm stuff you used?

It was close to decade ago, but I'm sure it was these

 

[Ian H]

Cheers, I think one pack would do us

 

[Ian H]

The sections I need to do are 3 x odd shaped triangles.

For fixing should I fix to my last rafter, to the floor, and one into the chimney breast? Like this with the white bits being screws:

 

[Ian H]

I've got some 50mm Rockwool Rockton acoustic insulation coming tomorow. It looks exactly what I'm after, the writing is mostly foreign but the pictures say it all really :

First one shows I can grope my missus while the neighbour sleeps, seconds shows I can chop someone up with a chainsaw while my neighbour browses porn and the third one I can drive a truck in the loft while the neighbour and his wife play with a train set.

 

[Ian H]

Made a start ready for the insulation:

 

[Ian H]

50mm behind the wood and 50mm between it:

It would take a bit more between the studs to fill it to the back of the boards, would you fill that with normal loft roll or leave a void?

 

[Doggit]

No point leaving a void; the last thing you want is the sound to creep through for the lack of detail.

 

[Paintguy]

First one shows I can grope my missus while the neighbour sleeps, seconds shows I can chop someone up with a chainsaw while my neighbour browses porn and the third one I can drive a truck in the loft while the neighbour and his wife play with a train set.

That sounds like excellent stuff

I'd agree with Doggit, might as well pack it full if you can. I know compressing loft roll is a big no no for thermal insulation, but it can't hurt and may even help acoustically so squish some in there.