soundproof - stud & resilient bars

Hi,

We want to cut out the noise from chatting, music and TV from our student neighbours - don't mind it in the day but not after say 11pm so we're going to try soundproofing

Along the party wall (2 alcoves and chimney breast) I was going to build a new stud decoupled using the approach lined out at the bottom of the post.

What I would like to know is:
Q1) Should I use resilient bars or is this overkill considering we will have 80cm of junk/clothes in front of the stud.
Q2) Is membrane between the plasterboard sheets overkill.
Q3) The wardrobe's hanging space will start at about 1.90m Our ceilings are 2.7m so alot of wasted space. I want to put in a large shelf in each alcove for storage. I will need to put some braces in the wall to support the shelf - if i screw these through the plasterboard and into the noggins of the decoupled stud will it undermine the soundproofing?

1.lifted flootboards in room above and floor and blocked the void and filled with insulation.
2. Leave 2cm gap
3. Put up timber 3x2 CLS studs unattached to party wall. On the 2 side studs and head/sole plate put a bead of acoustic sealent where they meet the surface.
4. Use rockwool flexi 70-100mm (seen sound blocker quilt plus is thinner and 4 times better but really dear) in the studs
5. 12.5mm soundboard screwed into the studs.
6. Another layer of 12.5mm soundboard so joins don't overlap
7. Acoustic sealent round the gaps
8. Skim
9. Sliding wardrobes doors . wardrobe will be 80 cm deep. The back 30cm will have heavy duty shelves for our boxes of junk and the fron 50cm will have double height clothes rail.

Cheers!

Resilient bars are good so once you've done all that you might as well use resilient bars as well - for the minimal cost. Membrane between the plasterboard sheets isn't adding anything though.

It's a student let next door, and you have relatively high ceilings, so presumably its a Victorian house? If so, many have party walls only 1/2 brick thick and if that's the case, what you propose doing would certainly improve matters.

Your spec. seems good and probably there is little else you could add that would be more effective, though resilient bars as above will help. But do bear in mind that it may not necessarily give you the sound reduction you aim for. There is still the issue of flanking sound transmission through adjoining walls and floors. So while you will certainly get some improvement, try to be realistic in what you hope to achieve.

Good luck with it - living next to students is never easy

Yeah it's a victorian terrace. Ground floor is fine as there is the guinell, it's the first and second floors that's an issue. The first floor bedroom share the space over the guinell - the party wall is on two steels running parallel I think the bricks are single thickness but i can see under the steels into the neighbours floor void . So I plan to fill this with insulation and see if i can put some bricks or cement board to give it some mass.

Anyhow on the stud, if i put resilient bars I've read if done correctly it should give some flex.

Would it be stable enough to screw through the two soundboards into the resilient bar to fix a brace at the back and one side (the other side is a brick non party wall) and then we would put a 18mm shelf about 1.17m x 0.60m. The shelf would be taking bulky lightweight items like duvets, sleeping bags, empty rucksacks/small suitcase.

If not i could always build a frame in front of the stud to help take the weight.

The problem is that you start listening for the slightest noise. Ear plugs are way cheaper and actually work.

joe-90 said:

Ear plugs are way cheaper and actually work.

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That's no help; how can he then listen to his own tv, or carry on a conversation?

JohnnyF said:

Would it be stable enough to screw through the two soundboards into the resilient bar to fix a brace at the back and one side (the other side is a brick non party wall) and then we would put a 18mm shelf about 1.17m x 0.60m. The shelf would be taking bulky lightweight items like duvets, sleeping bags, empty rucksacks/small suitcase.

.

Click to expand...

Can't quite follow what you mean, but it is vital that the boards are screwed through to the flexible (mesh) part of the bars, and that the screws do not penetrate to the structure supporting the bars themselves.
(Two boards can be screwed to the bars, with overlapping joists)
If you google resilient bars there's some informative stuff there.

tony1851 said:

joe-90 said:

Ear plugs are way cheaper and actually work.

Click to expand...

That's no help; how can he then listen to his own tv, or carry on a conversation?

Click to expand...

He can take them out. You don't glue them in ya know.

joe-90 said:

He can take them out. You don't glue them in ya know.

Click to expand...

Well, if he takes them out to watch tv or have a conversation, the noise from next door becomes audible and competes with what he is trying to listen to.
You clearly haven't had noisy neighbours - it can drive people desperate.

I think he's talking about going to sleep when it's all quiet. You keep listening for it - that's the killer. You need to desensitize yourself first and ear plugs are good for that.

I tried the ear plugs route a couple years ago - and didn't get on with it, they weren't the most comfiest and i think my sinuses went funny. Last year we kipped in the box room away from the students and doing the same at the moment but would be nice to be back in the main bedroom with the ensuite. My snag is i used to work shifts so used to being able to function on a couple of hours kip. If I get woken up it's hard to get back to sleep then i'm knackered and grumpy with the kids and missus. Well more grumpier than normal according to the kids

Just been reading all the posts here and seen a few by Deluks. He talks about leaving an air gap to the party wall and just fixing the head and sole plates to the floor and ceiling. What about the side studs against the non party walls (one is an external wall and the other is a supporting brick wall dividing the other bedroom) - do you put them up but say 5mm from wall and just attach to the sole and head plate and fill the 5mm gap with acoustic sealent?

If it works on this room I'll do the neighbouring bedroom next.

JohnnyF said:

Just been reading all the posts here and seen a few by Deluks. He talks about leaving an air gap to the party wall and just fixing the head and sole plates to the floor and ceiling. What about the side studs against the non party walls (one is an external wall and the other is a supporting brick wall dividing the other bedroom) - do you put them up but say 5mm from wall and just attach to the sole and head plate and fill the 5mm gap with acoustic sealent?

If it works on this room I'll do the neighbouring bedroom next.

Click to expand...

eh? Oh, hello that's me

10mm gap to be safe, but bear in mind, the bigger the airspace, the less noise will get through.
Your plan sounds fine, but fill the space with slabs of rockwool or the Knauf equivalent, if you can completely fill the void even better. Fibre insulation won't transmit flanking sound.

If you're tight for space, build it in 2x2, but it will need to be of sound construction, use angle brackets to hold it all together if need be.
The 2+ layers of plasterboard you add on top will stiffen it up, maybe make one of the layers of 15mm or 19mm plasterboard, and the other regular 12.5.

This is about the best you can do in a domestic situation without spending lots of money or doing lots of structural work. It won't be perfect, but it will be an improvement.

Building a separate wall AND using resibar is a waste of time and money, the resibar is designed to 'de-couple' the old from new when fixed to the wall. If it's not touching then its already de-coupled.

Cheers Deluks, just getting a list of stuff I need before going to a couple of builders merchants to get quotes.

So you would say forget about the resilient bars for a separate stud? I've read they will stop more impact noises. I reckon I need 12 so at about £4-5 each it won't cost the earth. But again if no benefit then happy to give it a miss. But with that weight of the plasterboard i'll need noggins - where noggins are there won't be rockwool so would i be better with resilient bars?

Also the air gap - does this have to be completely clear? I've seen one site that suggests 50mm stud and 20mm airgap and 70mm insulation. That means the insulation would be in the airgap. Is that OK for it to be right up to the wall or is it better leaving 2cm totally clear?

I'm going to use 3X2 CLS and was going to get 70mm rockwool. If the airgap doesn't have to be clear then I can put in 90mm rockwool.

Cheers for all the advice too

JohnnyF said:

I'm going to use 3X2 CLS and was going to get 70mm rockwool. If the airgap doesn't have to be clear then I can put in 90mm rockwool.

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^Do that^ with the 90mm rockwool too, you'd even get away with 100mm and slightly compressing it.
Resibar...your money, your call. Get the screwing detail right though.

Cheers will work out what i need and get ordering