Metal Stud Walls - How much acoustic protection is too much?

[Tony K]

I am using metal stud walls (70mm studs) for all internal partition walls, most commonly between bedrooms and bathrooms. 

The various metal stud wall suppliers offer different details and configurations that can be achieved using their products (different ways to build internal partition walls, basically).

Each option has a stated sound rating. Presuming I want to stay around 100 - 130mm total wall thickness, my options seem to range from 34-63 RwdB (e.g British Gypsum GypWall Single Frame) to 61-65 RwdB (e.g GypWall Resilient). 

 

Building Regs require 40/45db, which I understand is (firstly) likely to be achieved by a basic frame with insulation in the void and (secondly) not an especially high level of noise insulation.

 

Within my wall width-limit I can see a few options that get me up to 60-65 db though, of course, the cost goes up. I understand the basic principles involved and can probably create a wall of my own design using cheap studs, decent insulation, a gap, and some combination of acoustic and/or standard plasterboard. 

 

I would be interested to know...

 

1. In reality, how much difference would I actually notice between a 40-45 db wall and a 60-65? We have very small bedrooms in a terraced layout and we want a nice, quiet house so I don't mind the extra cost, but I don;t want to waste time and money if the benefits are negligible.

 

 

2. Does anyone have any good tips for creating a good (and reasonably priced) internal metal stud wall with high sound insulation qualities? I am thinking perhaps a 70mm stud, 50mm insulation, a 15mm airgap on one side of the insulation, standard plasterboard on one side of the wall and double skin on the other, but if anyone has a better recipe then please do share!

 

Cheers

[Mr Punter]

13 minutes ago, Tony K said:

how much difference would I actually notice between a 40-45 db wall and a 60-65?

 

The difference will be huge.  The doors will be the weak point.

[Conor]

We've 70mm metal studs, standard boards and 50mm isover accoustic roll inbetween... Can't hear a thing through them. Keep it simple, keep it standard.

[Mike]

8 minutes ago, Tony K said:

how much difference would I actually notice between a 40-45 db wall and a 60-65?

A cut of 10db = a halving of noise, 5db = a useful reduction, 3db = just about noticeable. So to go from 40dB to 60dB the airborne noise level would be a quarter of what you'd otherwise hear - a very significant difference.

 

If impact sound is an issue, then you'd ideally want two independent studs, though resilient bars are an option. This is the one I'll be building later this year; 2 x 70mm studs, 2 x 45mm hemp sound insulation, with 1 x plasterboard + 1 x GypsoLignum each side. I'm expecting a reduction around 65db, though as I'm using GypsoLignum I can't prove that.

 

[nod]

If you have any particular room that you would like to soundproof ie bath to bed Use two 50 mil stud walls 50 mil apart braced with 150 off cuts of track each stud every 800 vertically

15 mill soundblock You won’t even hear the loo flush 

[Tony K]

37 minutes ago, Conor said:

We've 70mm metal studs, standard boards and 50mm isover accoustic roll inbetween... Can't hear a thing through them. Keep it simple, keep it standard.

 

Did you establish (either before, after or both) a dB level for that arrangement? 

[Tony K]

36 minutes ago, Mike said:

This is the one I'll be building later this year; 2 x 70mm studs, 2 x 45mm hemp sound insulation, with 1 x plasterboard + 1 x GypsoLignum each side. I'm expecting a reduction around 65db, though as I'm using GypsoLignum I can't prove that.

 

 

What overall wall thickness is your design @Mike? 

[Tony K]

29 minutes ago, nod said:

If you have any particular room that you would like to soundproof ie bath to bed Use two 50 mil stud walls 50 mil apart braced with 150 off cuts of track each stud every 800 vertically

15 mill soundblock You won’t even hear the loo flush 

 

That'll be quite a thick wall wouldn't it? 

[Conor]

3 minutes ago, Tony K said:

 

Did you establish (either before, after or both) a dB level for that arrangement? 

No, it's standard, exceeds BC, and I didn't think about it. 

[Tony K]

1 minute ago, Conor said:

No, it's standard, exceeds BC, and I didn't think about it. 

 

I have to say my instinct was the same. Interesting that it's been fine for you. I presume you have the standard domestic noise levels etc (kids, dog, wife... 😉)? 

[Conor]

7 minutes ago, Tony K said:

 

I have to say my instinct was the same. Interesting that it's been fine for you. I presume you have the standard domestic noise levels etc (kids, dog, wife... 😉)? 

 

Yes, the house is eerily quiet. And we've either laminate, LVT or carpet in all rooms... We were paranoid about lots of echo in the open areas, but it's fine. Concrete floors and fire rated doors help a lot as well.

 

I also beleive we have not only limited time, but limited physical and emotional energy... Are there other things you could be spend this energy on? Definitely my biggestes lesson learned from building a house.

Edited March 29, 2023 by Conor

[Mike]

1 hour ago, Tony K said:

What overall wall thickness is your design @Mike?

170mm.

 

2 hours ago, Mr Punter said:

The doors will be the weak point.

Yes. Allow for heavy doors with edge seals & beef up the stud that the frame fixes to - you'll probably need a double vertical stud (check what the stud manufacturer says about supporting heavy door sets).

[Tony K]

2 hours ago, Conor said:

 

I also beleive we have not only limited time, but limited physical and emotional energy... Are there other things you could be spend this energy on? Definitely my biggestes lesson learned from building a house.

 

Amen to that! 

[Tony K]

For those with an interest, I spoke to a soundproofing firm who were quite approachable and realistic. They offered me a design achieving 61db at 160mm thick, which I just don't have the space to do. In conversation they suggested a standard wall comprising 70mm metal frame, 50mm acoustic insulation inside, 12.5mm plasterboard on either side and then, finally, the addition of this stuff to one side of the wall only:

 

https://soundproofingstore.uk/product/prosound-soundboard-4-stud-walls/

 

Total wall thickness 125mm. 

[Thorfun]

1 hour ago, Tony K said:

For those with an interest, I spoke to a soundproofing firm who were quite approachable and realistic. They offered me a design achieving 61db at 160mm thick, which I just don't have the space to do. In conversation they suggested a standard wall comprising 70mm metal frame, 50mm acoustic insulation inside, 12.5mm plasterboard on either side and then, finally, the addition of this stuff to one side of the wall only:

 

https://soundproofingstore.uk/product/prosound-soundboard-4-stud-walls/

 

Total wall thickness 125mm. 

for clarity.....12.5mm plasterboard on EITHER side means only on one side with the linked prosound-soundboard on the OTHER side, right? not 12.5mm plasterboard on both sides with the additional soundboard on one side?

[Tony K]

2 minutes ago, Thorfun said:

for clarity.....12.5mm plasterboard on EITHER side means only on one side with the linked prosound-soundboard on the OTHER side, right? not 12.5mm plasterboard on both sides with the additional soundboard on one side?

 

It is the latter, so 12.5mm plasterboard on both sides with the additional soundboard on one side

[saveasteading]

21 hours ago, Mike said:

two independent studs, though resilient bars are an option

Either of these is my preference. 

The rated performances are rarely achieved in practice (these are lab test figures) so go for the best rated that works for the width available.