Soundproofing an internal stud wall

air

Hi guys,
I'd like to improve the soundproofing between two of the bedrooms in my house, one of the rooms is smaller than the other so I'm planning on putting the extra material on the inner side of the adjoining wall in the smaller room to minimise the work.
I'm replacing the flooring at the moment, skirting off etc so it's just down to a bare wall.
I've read this recent thread - http://www.boards.ie/vbulletin/showthread.php?threadid=2055550642 - which is more focused on party wall sound insulation.

I'm wondering what if anything I could fill the cavity in the stud wall with to help matters?
Current plan is to batten the wall, fill gaps between battens with some rockwool & then add another 12mm layer of plasterboard on top of this.
Should be easy enough to find someone to skim it I'd imagine.
I'll probably also replace the internal door as it's pretty lightweight as it stands.

PirateShampoo

Just pull of the Plaster board from one side and fill the between the Studs with 100mm Rock wool (or what ever deph the stud is), then replace the plaster board. For a little bit extra double slab each side and make sure u stagger the boards so the second skin over laps the joints of the first. Then replaster.

Should be more than enough.

air

Cool, sounds good. Any tips on removing the original plasterboard without destroying it?
Also ballpark figure on replastering? 6.5sq metres of wall.

gsxr1

Pirate is bang on.

Exactly how I would approach it also

PirateShampoo

Dont think ul remove it without destroying it, even more so if its plastered. You only have to remove it from one side though if its any consolation.

air

Ah no bother, sure at least I won't wast time trying anyway now
Not like the plasterboard sheets themselves are very expensive either anyway. Thanks for the tips, will give it a lash.

PirateShampoo

No problem, you should pick up a plaster for a decent price these days also.

air

Any ideas where to look for one? I'd imagine it'd be pointless looking for a company for such a small job.

PirateShampoo

Id check the local ads in the paper. Always lads looking for jobs there.

BUILDERSKY

Hallo Air
You can consider a sound proof plaster slab wich is 15 mm thick. and should cost 10,40 netto per slab. wich is not much deerer then the ordinary one,
and you should put an acoustic silicon in the gap where slab meet ceilling, floor and side walls

air

Hi Builder, Thanks for the tips.
I've actually ordered the stuff already. I tore down the existing slab today & ordered up 6 sheets of 12mm plasterboard so it'll be 24mm thick overall. I need to locate a roll of rockwooll also to fill between the studs, only 75mm deep.
Adding a socket & relocating a light switch while I'm at it.

I've the skirting off in the adjoining room also so I'll be plastering that right down to the floor also. I think I'll get whoever is going to be skimming it to fit the plasterboard too since it shouldnt take him long when I've everything ready & would guarantee that it's done right.

PirateShampoo

U can get 75/80 mm rock wool mate. Brooks/Heatons/Chadwicks will all have it.

air

Super, was in B&Q last night & they had none, will get some today then.

BUILDERSKY

maby you can plaster it youself. its very easy.
get a bag of fastset(12euros) apply on joints where slab meets slab or ceilling or walls (should take 30 min) then get bucket of sheetrock (blue cap 20 euros) apply on every uneven surface let it dry (1-2 DAYS) then get sanding paper and sand until obtain smooth surface
and then its ready to be painted

.,.,.,.,.,.,.,.,great fun doing it guaranted,.,.,.,.,.,.,.,.,.

air

Right, I was under the impression that I'd need to skim the whole thing & that it was pretty specialised.
If I understand it correctly this is a method to just smooth over the joints etc by taping over them with the netted tape type stuff & then filling over & sanding?
Sorry for the ignorance, have never seen this work in action.

PirateShampoo

Buildersky is talking about Tape and Jointing, its simple enough to do.

https://www.youtube.com/watch?v=8iEIdWEMQ6Y

You wont get that type of tape in this country though. but we have stuff similar.

BUILDERSKY

yeah that's the thing

the tape u can get in any supplier, stuff for first coat is a fastset in 10 kg bags so u need to mix it with a water up to butter consistence.
put it on the joints and other hols or gaps or uneven surfaces also on minimash corners around window, doors etc, just to make level.
when its dry (next day) apply a shetrock wich is ready mix in 20 kg buckets
its easy to sand so u can put a small bit more

good luck

air

Cheers lads, I think I'll give it a go so.
Buildersky, by the looks of the video they are proposing that you can just get away with skimming over the tape and not putting on any sheetrock coat. One of the guys in the vid mentions that the painters can start the following day after the joints are smoothed down.
I recall a colleague telling me that the IBIS hotel at the Red Cow was done using this method, ie seams just taped & gone over.

I think I'll try smoothing over the tape & see how it looks after sanding, if it's crap I'll probably get someone in to apply the sheetrock.
It's a simple square of wall, no doors, windows or anything else to deal with.

BUILDERSKY

and one more thing
the plaster slab was created to use like plaster so it means it is plaster
they are made from gypsum and it has interesting property. when air in room is wet the gipsum is taking humidity like sponge, when air gets dry gives it back,
if u skim whole surface it'll never work that way