Accoustic insulation

[malky boi]

I plan to revamp my workshop in the new year. It's a double garage, single concrete block, rendered and has a slate roof. The only entry is the garage door which is insulated and about 5 years old. I plan to put in a seperate single door and a couple of windows.

I have had some remarks from a neighbour (we have 8 adjoining properties) about the noise when running the machinery. So I was wondering about acoustic insulation while I was at it. Does anyone have any experiences in this area? There lots of products on the market that may do what I want, both thermally and acoustically. I am particularly concerned about stopping any noise pollution from the workshop, but will I end up working in a loudspeaker?

Anyone got any thoughts or been down this avenue?

 

[Beau]

R60 rockwool is very good at absorbing sound. Did a large soundproofing job a few years back and used this inside very large enclosure. It worked great when exposed to the sound but due to concerns about dust getting trapped and fire had to line it with sound block plasterboard mounted on resilient strip which reduced it's affected greatly.

 

[clk230]

Sorry to disagree Beau but adding another layer of material won't let more sound out of a room , different materials will have more or less sound absorbing properties at different frequencies though.

 

[Beau]

Sorry yes did not make my point well. If the room is well sealed another layer will help avoid the noise escaping but my job could not be well sealed so it was less effective. malky boi mentions not wanting to turn his workshop into a loudspeaker and lining it with soundblock plasterboard could well make it it pretty nasty in there but help with the escaping noise.

 

[blackrodd]

I've had some experience of sound attenuation, through working on night club upgrades and also supermarkets, acoustic and environmental partitions and ceilings.
Rather than bore the pants off us all by me trying to remember things, I suggest you Google "Sound attenuation materials". and you can mug up on the subject.
Rockwool cavity batts will probably be easiest for sound absortion, and good old 1000 gauge polythene to stop carrying by movement by air, using each or both as the barrier.
Perhaps it would be possible to leave an area untreated, which would be on you're house side of the workshop.
So workshop walls, facing neighbours, and roof are lined
Fibre board under the machinery feet too, to combat sound carried by vibration
Basically, as mentioned, you will need to absorb sound more than move it elsewhere.
HTH Regards Rodders

 

[Steve Maskery]

You could try PMing Eric The Viking. He was a sound engineer and knows everything about everything. Really.

My own understanding extends to knowing that lots of different layers is more efffective than just one layer. So my workshop has, inside to outside, plasterboard, timber and celotex, OSB, membrane, air gap, cempanel.

Last week I was up a ladder at the back and Ray took in a length of wood to cut. He brought it back the right length and I asked him how he had cut it. He'd used my SCMS, just a few feet away from me, and I'd not heard a thing.
S

 

[Zeddedhed]

My workshop is constructed from (outside to inside) Siberian Larch cladding on 25mm battens on Membrane (Tyvek) on OSB on 5 x 2 studs with 100mm celotex between on 12.5mm plasterboard on 18mm ply on plaster skim. The final inside layer is thick dust, but I doubt that makes much difference.

I can run my machines in there in the middle of the night (and sometimes do when the pressure is on) and you can't hear any more than a faint murmur once you're 2metres away.

 

[Roughcut]

I've been insulating the "shed" and have used a mixture of Rockwool type insulation (due to availability and convenience).
I used the Wickes General Insulation Slabs and genuine Rockwell Flexi Batts.
Both of the above are said to provide Thermal and Acoustic Insulation properties.
The Wickes stuff was the first one I used due to being an easy local pickup but it's not great and falls apart when handling, and fills the air with loose fibres.
So I then ordered the genuine Rockwell stuff and it is great, much easier to handle.
I then sealed the whole lot with a Polythene Vapour Barrier which will be boarded over.
So in short use a good dense Insulation, seal all gaps, board or double board over.
There are acoustic plasterboards available but I'm not sure how good they really are?
When I've read some documentation on the subject it seems that they use 3 layers of the plasterboard for their decibel testing = expensive and not always practical in the real world.

 

[MattDenny]

FYI Knauf make a perforated plasterboard called Apertura which works very well. It reduces reverberation and the perforations allow a certain amount of sound through into your Rockwool meaning that the acoustic qualities are not completely shut off.

Knauf products are mostly distributed by drywall and suspended ceiling wholesalers. There may also be a British Gypsum/Lafarge equivalent.

Regards
Matt

 

[mindthatwhatouch]

Good advice above for the structure.
You could always add a sound absorbing panel (wooden frame, foam covered with carpet) or two on the interior if you find its reverberating a bit.

 

[blackrodd]

Our local Wickes, here in Sunny Devon stocks Knauf products, so this may be other depots stock items too!
Regards Rodders