Partial timber stud between reception rooms - how would you reduce noise transmission through it?

[low_and_there]

We've got a 100mm timber stud in an aperture between the front and rear reception rooms (it's about 80% of the wall - the rest is solid brick), and as part of wider works, the plasterboard is off (on one side), the floor is up, it's all bare bones, and I have the opportunity to improve the acoustic insulation / sound absorption it provides.

 

One of the things I'm trying to figure out is whether to rip off the remaining plasterboard on the other side to replace with SoundBloc. We've not got particularly loud noises to absorb, just TV noise / music from front to back rooms, so I don't believe it's necessary to go down the Resilient Bars route.

 

Any thoughts on how you would tackle this?

 

Current thinking:

a) wool insulation between studs (100mm gives 40db reduction, or so the technical spec claims) - personal preference not to use mineral wool

b) 15mm Gyproc SoundBloc boards either side - apparently a density of 840kg/m³

c) Isolation strip (like 'karma') under the skirtings along either side of the wall (but could / should I use it elsewhere?)

 

What else? Is it worth using any 'acoustic' sealant on the edges for example?

 

Or what about a 12.5mm SoundBloc, combined with something like 6mm Ply (I've got the depth to do this on one side) - I've read that different materials layered can be better than thicker of the same material - is it worth it / necessary in this context do you think?

 

Thanks!

 

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Bit more detail on the context:

 

- Stud wall is standalone and does not sit on joists (joists stop short of the stud on either side, resting on sleeper walls)

- I've made sure the electrical sockets are not back-to-back and have placed acoustic putty pads in the socket boxes

- new OSB structural deck aligns to the end of the joists, so is 'decoupled' from the wall

- will ensure rest of floor construction is also kept apart (UFH in 35mm biscuit mix dry screed 8:1 sand:cement) and 15mm engineered wood boards)

- we've got wool insulation under floor (200mm) which I'm thinking may dampen impact noise

-  The stud was originally built above the original floorboards (there would have been doors between the rooms when the house was built), and is actually only secured to the side and upper walls; the base plate is currently floating 100mm above a brick sleeper wall - as I do not want to rebuild the stud I'm planning to wedge noggins under the base plate to give it something to rest on when laden with weight.

- I'll put 100mm wool under the base plate of the stud between noggins (which I've staggered from joists)

[Nickfromwales]

Resilient bars are defo the wrong product, so I think you’re on the right path with your thinking. 

There are sound block rubber matting type solutions available, and I’d install that at the 6mm thickness, or 10mm if you can manage that, eg instead of the ply. 

[Nickfromwales]

The rubber makes a huge difference. I now use Killmat on any waste pipes over ground floor bedrooms / snugs etc as it works so well with the high frequency stuff, like water splashing etc.

 

 

 

Edited July 7, 2022 by Nickfromwales

[Nickfromwales]

[JohnMo]

You don't need to full fill space with insulation, it then acts to transfer noise.  70mm will be better, so it has an air gap.  The material you use (wool or whatever) needs to be able to self support it's self between the studs, so it doesn't slump over time.

[Nickfromwales]

5 minutes ago, JohnMo said:

You don't need to full fill space with insulation, it then acts to transfer noise.  70mm will be better, so it has an air gap.  The material you use (wool or whatever) needs to be able to self support it's self between the studs, so it doesn't slump over time.

Yup, and that’s why we use the string where there may be a risk of it dropping / slumping over time.

[low_and_there]

33 minutes ago, JohnMo said:

You don't need to full fill space with insulation, it then acts to transfer noise.  70mm will be better, so it has an air gap.  The material you use (wool or whatever) needs to be able to self support it's self between the studs, so it doesn't slump over time.

right, cool, noted! Thanks @JohnMo

[Temp]

If you can, consider two lots of studs one for each side of plasterboard with insulation loose fitted between. Sometimes floors done this way.

 

Not really to scale..

 

[low_and_there]

40 minutes ago, Nickfromwales said:

I now use Killmat on any waste pipes over ground floor bedrooms / snugs etc as it works so well with the high frequency stuff, like water splashing etc.

This looks to be a brilliant idea - adding to my list for when we come to install the new pipework, thanks for sharing the photos @Nickfromwales

[nod]

When you put your boards back on 

Don’t forget to stager either side 

ie Start with a full board on one side Then start with a  half board on the other side 

A layer of gyproc plank laid on horizontally will dramatically reduce noise 

[low_and_there]

2 minutes ago, Temp said:

consider two lots of studs one for each side of plasterboard with insulation loose fitted between. Sometimes floors done this way

I can’t (or rather don’t want to!) rebuild the studs, but what if I alternate the verticals and/or horizontals that I secure the SoundBloc on each side to..? 
 

They’re at 400mm centres horizontally, 600mm vertical. 

[low_and_there]

1 hour ago, Nickfromwales said:

here are sound block rubber matting type solutions available, and I’d install that at the 6mm thickness

 Excellent, thanks for the steer @Nickfromwales.
 

In terms of installing it, I put that up on the studs first, then the SoundBloc on top - is that right?

 

Do I want the rubber to be sealed at the perimeter and at joins in the sheet as well?

 

thanks (a thanks for now and a thanks for every time my kids watch loud movies while I’m working late in the room next door!) 

 

[Nickfromwales]

8 hours ago, low_and_there said:

 Excellent, thanks for the steer @Nickfromwales.
 

In terms of installing it, I put that up on the studs first, then the SoundBloc on top - is that right?

 

Do I want the rubber to be sealed at the perimeter and at joins in the sheet as well?

 

thanks (a thanks for now and a thanks for every time my kids watch loud movies while I’m working late in the room next door!) 

 

It just gets tacked on with a few nails / screws and the plasterboard screws go through both and into the studs.

An online example ( random grab ) LINK so you can check out their website to give you some ideas of the different products that are available to tackle this problem.