studded wall acoustic insulation

[Lancashirelad]

Hi All.

I am in the process of renewing the bathroom and wish to take the opportunity to insulate the wall next to a bedroom.

After a bit of research, I have the following ideas and would welcome your comments.

Rockwool flexislab 75mm RWA45 Does it need to be 60?

Unfortunately this will have to be cut as the gap between vertical timbers is only about 360mm
(what's best to cut it with - a pair of old manual sheep shears?)

The thought was to hold it in position by using a spray adhesive onto the back of the existing bedroom plaster board.

My further options for increased sound proofing are limited as the door frame, which is only a narrow frame, sits tight to the dividing wall.
There is just room to replace like for like 12.5mm plaster board.
So I can't space off with acoustic bars or fit 2 x 12.5 pb.

My own idea is to stick adhesive backed foam draft excluder tape onto the studs and noggins and then nail or screw the plaster board on as normal. Do you think this idea would work?

Or would an acoustic membrane be better?

The other option I thought of was to fasten the boards to the studs with green glue. (no foam tape).

Do I need to use sounbdbloc plaster board?

This wall will not be tiled, probably just painted after being skimmed & drying.

Bear in mind the following:

1. Cost IS an issue.

2. There was no insulation at all before, so anything is an improvement.

 

[Deluks]

How thick is the wall?

If you can't go thicker than 12.5mm PB then get the acoustic type.

Use full thickness RW, make sure board joints are over a stud (no chinks) Acoustic sealant the perimeter, not much else you can do really, but the rw will make a difference.

If you are only doing one side of the stud wall, then maybe slap a coat of bonding plaster on the inside back of the existing wall before you add the insulation. This will increase mass slightly and ensure there are no gaps in what's already there.

 

[Lancashirelad]

Thanks Deluks.

The studs are 75mm thick, so obviously total wall thickness is 75 + 2 x 12.5.

 

[Lancashirelad]

Hmmm, bit disapointed with the feedback off this forum.

<scratches head>

 

[seasickstevie]

What you disappointed about? Seems to me you've got the answer - what else do you need to know?

Don't get why you need adhesive for the Rockwool

Make it a nice snug fit between your studs. It ain't going nowhere.

 

[Deluks]

You could rotate the studs 90 degrees and do a staggered stud construction. Google it. (I just did and found a post by me on SFix forums from 5 years ago )

Not much more to say really.

 

[Lancashirelad]

Thanks for the replies guys. Found that 2006 post Deluks, very interesting. When I researched staggered stud wall & saw a diagram, I remembered, yes I've seen it before. Excellent idea, but in this case I have no intention of starting pulling the wall to bits. Gotta work with what's there.

Studs are 75mm so do you guys reckon I need to use 75mm insulation or, as mentioned in that other post, would 50mm be enough?

 

[mointainwalker]

Use 75 mm: this insulation is not hugely effective anyway, so you shouldn't skimp.