Rock wool for sound insulation

[Damonjames]

Hi guys n gals, not sure if this is the right spot for this but here goes. I am building a practice space in my garage, which will consist of stud timber frame with sound deadening plasterboard. I was going to use rock wool in the cavity for additional sound insulation but that stuff is expensive 😳. Any thoughts on how effective it is for sound insulation, and any other more cost effective suggestions would be greatly appreciated. Cheers!

[BigRedX]

You have to use the right type as there are many different versions of Rockwool with different unit masses. Studio Spares recommend the RW3 variety as offering the best compromise of weight cost and noise attenuation.

The main use of Rockwool and similar materials is no so much sound insulation, but more to do with filling up the spaces in stud walls that would otherwise be producing nasty resonances. It will have little effect on bass frequencies, and the only way the really tackle these is with lots of mass (solid walls, many layers of plasterboard) and decoupling the extra mass you add to the walls ceiling and floor from each other and from the original structure.

[bremen]

What Mr Redex said, plus making it airtight is crucial.

Also: http://www.soundstop.co.uk/

[MiltyG565]

[quote name='BigRedX' timestamp='1366615422' post='2054750']
You have to use the right type as there are many different versions of Rockwool with different unit masses. Studio Spares recommend the RW3 variety as offering the best compromise of weight cost and noise attenuation.

The main use of Rockwool and similar materials is no so much sound insulation, but more to do with filling up the spaces in stud walls that would otherwise be producing nasty resonances. It will have little effect on bass frequencies, and the only way the really tackle these is with lots of mass (solid walls, many layers of plasterboard) and decoupling the extra mass you add to the walls ceiling and floor from each other and from the original structure.
[/quote]

Yes.

It's not really designed for sound insulation, just heat insulation, but because of the design of it, it gives some sound protect, as BRX said, it will stop all the air inside the cavities rattling around, which i'm sure would get annoying. It's messy stuff to put in though. I used to put a jumper on before putting it in, then take it off when finished. It's less irritating that way, because not as much of it gets in touch with your skin.

[Monckyman]

The best stuff I've found is the slab stuff, as you can cut it cleanly and wedge it between your stud work.
There used to be lots of bogof offers on insulation but they all seem to have stopped at the mo,maybe next autumn..
Have a look on eBay,there are quite a few slight seconds and unused stock traders offering good prices, but its all about the delivery charge so see if you can go local.
As to alternatives,perhaps some of the sheeps wool stuff would be as effective as rock wool, not sure about the rubber chip insulation.
The foam insulation boards like Kingspan etc offer no sound attenuation at all.
You might also explore the practicalities of using two layers of soundboard slightly overlapped so the joins are staggered.
My cheapest quote (in Manchester) for accoustic plasterboard is £7.00 a board, so app £100 for that extra layer.

I'm currently installing a control room area in my rehearsal space and am using this method, though I don't think there is a way around the rock wool.
Good luck!

[leschirons]

Proper acoustic insulation is expensive. Over the last few years here, I've been involved with quite a lot of dry lining work including two rehearsal studios (mine and a friend's) I used the real stuff for mine from a local company called Eurocoustic but only because I got some B stock with damaged boxes. Rocwool is not really dense enough to make a difference as it's more designed to have good thermal protection qualities. The good stuff comes in panels and is much more dense and heavy.

As BigRedX points out, the secret is layers. I'm assuming that you'll be partitioning off say, half of your garage and that some of the walls will be brick. Best to put up some stud work, fill that with the cheap stuff, board it (10mm board will do) and then another layer of stud on top, fill that, and then board with 13mm, compacting each layer of insulation as much as possible each time.

Of course, if you're leaving any windows in the studio section, they would ideally need to be covered too but you'll never really be able to completely isolate 100% of the sound.

[MiltyG565]

Egg cartons, they'll do the job just as well. Glue a load of them on.

[bremen]

[quote name='leschirons' timestamp='1366616600' post='2054772']
Proper acoustic insulation is expensive. Over the last few years here, I've been involved with quite a lot of dry lining work including two rehearsal studios (mine and a friend's) I used the real stuff for mine from a local company called Eurocoustic but only because I got some B stock with damaged boxes. Rocwool is not really dense enough to make a difference as it's more designed to have good thermal protection qualities. The good stuff comes in panels and is much more dense and heavy.

As BigRedX points out, the secret is layers. I'm assuming that you'll be partitioning off say, half of your garage and that some of the walls will be brick. Best to put up some stud work, fill that with the cheap stuff, board it (10mm board will do) and then another layer of stud on top, fill that, and then board with 13mm, compacting each layer of insulation as much as possible each time.

Of course, if you're leaving any windows in the studio section, they would ideally need to be covered too but you'll never really be able to completely isolate 100% of the sound.
[/quote]

Part of the secret is the layers. It's important to decouple the plasterboard from the brickwork though, ie mount it resiliently, or the lower frequencies just go straight through. Soundstop.co.UK have loads of information (and numbers)

[51m0n]

BBC white papers are your friend.

They ahve done exhaustive research into the most effective bang for the buck sound attenuation with different partition wall designs. You must decouple walls from floors everywhere, and ceiling too. You absolutely do need to caulk everything, and to take into accoun that you need air from somewhere. The number of layers and even more inportantly the number of spaced layers (never three, two is significantly better) is hugely important. As is using different density/thickness material (plasterboard and soundboard layers together v. effective) for each layer (each layer has different resonances then). Always always fill any voids with insulation, definitely RW30 or RW45 (again investigate those white papers) as otherwise you get lots of resonant pockets in the walls which carry sound.

Surface mount all the sockets, because anything that involves a hole in your wall lets air through.

Do make a proper sound deadened channel for air into and out of the room or you will struggle with over heating.

Doors are the biggest loss poitn, and good sound proof doors are mega expensive. A solid soor with a couple of layers of plasterboard/sounboard on each side over a layer of sound matting will get you a long way if they seal correctly when closed. Two of these a few feet apart and you are as good as you can get without spending silly sill money.

You could consider a floated floor (on tennis balls) it works....