Stud wall insulation

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Hi all,
I am in the process of building a stud wall to divide a room in two.
The room was divided originally when the house was built but the previous owners knocked it down to make the master bedroom bigger.

I wish to put it back. The walls upstairs are all stud walls of 60mm thickness. I am going to make the new wall slightly thicker as I have the wood already. My question is does the isulation have to fill the thickness of the wall compleatly? The stud thickness is 47mm. Could I use 50mm Celotex board and compress it by the 3mm, or use thinner insulation.

Any recommendations?

Many thanks.
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[PrenticeBoyofDerry]

I would use slightly thinner insulation or pack your walls out to 50mm,
as kingspan/celotex is quite rigid stuff and could effect the fixings of the plasterboards, rockwool will be as good as anything.

 

[ads1]

Thanks. i think rockwool is cheaper and as it is an internal stud wall, insulation is not as important. If I go for 50mm Rockwool would this be ok to compress slightly to the 47mm stud thickness?

 

[freddiemercurystwin]

You can easily compress Rockwool a bit. You realise you don't actually need any unless its between a bathroom/toilet and another room. Crown Acoustic Partition Roll is another alternative.

 

[ajrobb]

Thanks. i think rockwool is cheaper and as it is an internal stud wall, insulation is not as important. If I go for 50mm Rockwool would this be ok to compress slightly to the 47mm stud thickness?

Thermal insulation between rooms is a 'nice to have' option to support zoned heating. I doubt the insulation needs to meet external wall values. 50mm acoustic mineral wool will easily compress to 47mm and give 'good enough' thermal insulation between rooms plus a slight sound deadening effect.

You could make an acoustic partition to reduce sound transmission.

 

[ads1]

Thanks guys, think that will do the job nicely. I thought best to put some in rather than nothing! Will also make the wall sound a bit more solid!

Don't think i need an acoustic partition, as it is between two bedrooms, and will have more insulation than when it was first built anyway. Thanks for the link though interesting to know this stuff for future reference.

 

[mointainwalker]

I would suggest using 100 mm fibre wool compressed to give best acoustic insulation ( if this important to you) without significant expense. This is the maximum I have found I can reasonably squash into a 50 mm cavity.

In any case fibre-wool offers better acoustic dampening than a rigid board and , squeezed as above, does make the wall feel and sound fairly solid when tapped.

 

[joinerjohn]

I've just done a stud wall out of 50mm x 75mm timber and put rockwool in it Hard enough to squash down to that.

 

[ads1]

I'm only talking about squashing the Rockwool 3mm. I presume you were using 100mm Rockwool and a 75mm stud, therefore squashing 25mm, which i guess would be more tricky. I hope I'm right anyway as I was going to use rockwool.

 

[mointainwalker]

No. Why do you assume that ?

This is the maximum I have found I can reasonably squash into a 50 mm cavity

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What I posted was accurate: 100 mm into 50 mm cavity, The denser it is, the better the acoustic insulation.

 

[ads1]

It would seem rockwool is harder to obtain around my area. Is Isover the same stuff?
They do it in rolls a bit like loft insulation.

Many thanks
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[mointainwalker]

No it is not the same stuff but just as good in this application which is why I referred to fibre-wool.

 

[ads1]

Many thanks. I guess any fibre wool will do the job I want. But the isover says it is acoustic roll, so would hope it is better for the job.

 

[mointainwalker]

That's just marketing nonsense, They have all started saying that now.

Same thickness/density same effect. Buy the cheapest , or if you are sensitive to the yellow stuff, buy one of the newer roll materials like Knauff Ecose - brown and not unpleasant to handle,

 

[ads1]

Thanks mointainwalker.
As I am also doing the loft insulation, I will just use the left over 100mm thick stuff, as that should compress in to the cavity nicely. Plus its cheaper.