Studwork soundproofing nightmare

[boxman2000]

Right, where to start. Firstly let me apologise, I’m not a builder or much of a DIY enthusiast (actually an accountant that can just about use a hammer!) I’m struggling to find good advice on soundproofing and fortunately came across this site which has been invaluable so far - hopefully someone can help us!

Anyway, 7 years ago we purchased a semi-detached house (1 house split into two) which I only recently found out was done after a fire broke out in the loft several years ago. The house is a 1960's single cavity build.

All was well until a new family moved in with a young girl (11 going on 18) and a 3 year old boy, both of whom have numerous tantrums and certainly have healthy lungs!

To our horror we soon discovered the partitioning wall between the two properties is only a standard single depth studwork with fire retardant boarding/plasterboard. The two staircases run next to each other but cross in the middle rather than running in the same direction (if that makes sense).

Subsequently, due to this bodge of a partition we can hear them running up and down the stairs, conversations they have by adjoining walls and worst is due to their bathroom backing onto our master bedroom we can hear…. well more than we would like.

We have had a couple of builders coming in giving us crazy quotes (over £10k) for things like ripping down all plasterboard, adding further stud partitioning and even removing staircases (3 story property) and putting proper walls in etc.


My questions are:-
1) What is the best material to fill between the joists and what kind of soundproofing plasterboard is best?
2) Same question goes for filling inbetween ceiling joists.
3) What (if anything) can be done to deaden the sound coming from the stairs?


The neighbours are actually really nice and they certainly don’t intentionally make noise but just as the adults are careful the kids couldn’t give much of a toss. They don’t have much money due to building an extension so getting them to do any work their side is virtually nil.

Appreciate your time and any advice you have.

Thanks
Pete

 

[PrenticeBoyofDerry]

There are lots of sound insulation products on the market that can infill between the stud wall and the floor timbers.
http://www.noisestopsystems.co.uk/soundproofing-walls-6/

Your side of the stud (plasterboard will need to be removed) this when the wall is sound insulated, can be boarded over using soundbloc boards
http://www.british-gypsum.com/produ...ssories/gyproc_acoustic/gyproc_soundbloc.aspx as an additional.

Do your neighbours stairs have carpets installed? If not that will helkp reduce deflected noise.

 

[boxman2000]

Many thanks for the reply and the recommended products.

To answer your question yes they do have carpet but they were 'thinking' about installing rubber underlay.

 

[PrenticeBoyofDerry]

Well that could be the way to go to reduce noise.

 

[Deluks]

bout the best you can do is to rip off all existing plasterboard, fill the cavity completely with rockwool, add resilient bar to the existing studwork and attach new PB/re-skim.
Bearing in mind that you will lose some room space as a result, which could be a problem where the stairs are...

Also check for gaps under the floorboards where joists may share a pocket hole in the masonry.

 

[amwc]

I can sympathise with you on this one I have exactly the same problem in my house. Its a nightmare I now talk in whispers every where I go. I ripped down the existing plaster board exposing the frame all the way to the roof. Then I build up a block work wall using brick sized thermolite blocks (this was as much for bracing as insulation, the bracing will help with the stairs a bit). then put two sheets thick PB back on the wall. Its a lot better than it was. and it was no where near 10k either more like 1.5K.

 

[alittlerespect]

Hi

Do a web search on 'phonewell' - 'phonewell' being a sound insulation system. When you get to the site choose sound proofing walls / Decoupled Batten Wall.

Should be of some assistance, which solution you choose will depend on the available space that you have!

Regards

 

[boxman2000]

Thanks folks, most appreciated all the advice given - more homework but at least I have a direction now

 

[PrenticeBoyofDerry]

No worries boxman2000, good luck with the project and if your ever scratching your head over something, you know where to come for advice.

 

[ajrobb]

Looking at the noise insulation charts, staggered studs are better than resilient bars at insulating noise. They don't have to be metal - the link is just to give you an idea. However, resilient bars can be used if noggins stop you fitting staggered studs. Use Soundbloc plasterboard or similar and 2 layers are better than 1. Use acoustic mineral wool rather than loft insulation type as it is more dense and absorbs more sound.

Because you are working on a fire wall between dwellings, you should contact your Local Authority Building Control and get their approval of any works before you start. If you have any sockets or switches on the wall, you might have to use intumescent boxes etc. 2 layers of 12.5mm Soundbloc should give 60 minutes of fire resistance.

Similarly, this kind of work probably comes under 'The Party Wall etc. Act 1996'.

Alternatively, leave the existing party wall intact (so you don't need permission or to notify you neighbours) and add 25mm battens aligned with the studs, acoustic mineral wool, resilient bars and two layers of Soundbloc. Go and chat with your LA Building Control, they might confirm it is OK. I can see the stairs being a problem though as you will lose about 75mm.

I hope the party wall is continuous from sub-floor to roof.

 

[Deluks]

I was gonna mention the staggered studs as a retrofit, but thought that there will almost certainly be noggins in there. Now you mention it do the studs have to be continuous? For example a stud stopping short of the noggin, and another going from just above the noggin to the top.

The existing studs and neighbours side plasterboard provide any structural support that the wall needs, and 2 layers of PB on 'this' side of the wall should be rigid enough to stay in place even if there is a break in the studs they are attached to.
Only problem I can see is the studs moving when you try and screw into them, now if you attached them using a heavy duty right angled bracket into the header/sole plates, and screwed in from top to middle, then bottom to middle? Is this making sense at all?

 

[ajrobb]

do the studs have to be continuous?

Acoustically, as long as they don't touch the noggins from the other side, that would be fine. Structurally, I'd worry that the plasterboard would crack at the gap - all the bending moments would be concentrated at their highest level in the weakest part.

I'm thinking of building a staggered stud wall between a bathroom and bedroom with a 25mm stagger. I'll put an 18mm floorboard between studs on one side for mounting a basin. However, in this case, a plank could run along the entire wall and be screwed to the top and bottom sections of the studs. You'd need to cut an accurate rebate in the studs to take the plank.

 

[Deluks]

Could also substitute the first layer for something more resilient such as mdf or ply. At the expense of fire resistance but the rockwool has good fire resistance anyway and must bring something useful to the party.
Fire resistant mdf could be handy here.

 

[ajrobb]

Fire resistant mdf could be handy here.

What about cement bonded particle board?

 

[boxman2000]

Alternatively, leave the existing party wall intact (so you don't need permission or to notify you neighbours) and add 25mm battens aligned with the studs, acoustic mineral wool, resilient bars and two layers of Soundbloc. Go and chat with your LA Building Control, they might confirm it is OK. I can see the stairs being a problem though as you will lose about 75mm.

I hope the party wall is continuous from sub-floor to roof.

We have not more than 2-3cm to play with as the staircase is so narrow.... unfortunately.

Thanks all for the additional info.