Sounbloc v Standard Gyproc

[Stoorice]

Hello, I'm Stuart and I'm new here.
I have recently moved house and my workshop is a single 5m x 3m garage that is attached to our house and located under the master bedroom.
My main concern is noise as this is a fairly new built house I would like to reduce the noise as much as possible that transmits through the walls and into the house when I'm working.
I have done a bit of research and figured hanging a second layer of plasterboard via a french cleat style system is probably my best bet as I don't want to compromise on space by adding a full set of stud walls.
Id like to hear from anyone that has used proper soundbloc plasterboard, was there much benefit over standard plasterboard, is it worth the 3x price tag.

 

[MusicMan]

I don't have experience, just acoustic theory! To get best isolation per mm you need the densest material you can, and this material should also be highly damping (opposite of resonant). Especially for low frequencies. I imagine that is what soundbloc does, and you may be able to find some figures on line. Also, you have to think of different frequencies. It would be worth stuffing something like rock wool into the gap between the wall and the plaster board to take out more of the high frequencies. Don't forget to seal the joins all round, as sound diffracts through small gaps, and don't forget the ceiling. Though that might be quite good anyway as I expect it is a fire-resistant board.

 

[Stoorice]

I've attached a sketch MS Paint image of what I want to do.
using 12.5mm board I should only lose 51mm per wall which I think is fine if it allows me to work in the garage once the kids are in bed.

 

[Jacob]

Might be good to make sure the new plasterboard is a different thickness to existing - then they resonate at different frequencies and transmit less from one to another. This works with double glazing - two panes with different thicknesses for sound reduction.

 

[Hot stuff]

I've used 15mm soundbloc but only in conjunction with insulation and framing. Very dense, very heavy and requires a bit of care handling, cutting and fixing.
It solved the problem we had but I've no way of knowing if standard plasterboard would have sufficed or not as it wasn't a replacement, just an addition. Given the previous comments regarding thickness and density I'd be quite hopeful that it would help in your case.
I'd be tempted to try it on the ceiling of your workshop first and see if it makes a difference, you'll need help to fit it and loads of plasterboard screws. One of those plasterboard lifts is a great investment, they appear regularly on gumtree and the like, easily sold on once you've finished with it.

 

[MikeG.]

Why would you put it on a cleat rather than fixing it properly?

Yes it works better than ordinary plasterboard, but with sound, it is ALWAYS the details which make all the difference (which is why I am cautious about making up your own detail with a cleat). The junctions around the boards, and between wall, floor and ceilings, and particularly doors and windows, are critical. I would ring the Whitebook helpline if I were you. They'll buzz you across their approved details, and I really wouldn't suggest varying from those as they are extensively tested.

 

[Stoorice]

id share a link but unfortunately, I can't yet due to account age, but the idea behind it is the same idea as resilient channel, Sound can travel through the walls of the house via vibration on hard surfaces. The idea is to separate the new inner wall from the rest of the house essentially and by separating the two halves of the cleat with a layer of foam roll/tape

 

[MusicMan]

id share a link but unfortunately, I can't yet due to account age, but the idea behind it is the same idea as resilient channel, Sound can travel through the walls of the house via vibration on hard surfaces. The idea is to separate the new inner wall from the rest of the house essentially and by separating the two halves of the cleat with a layer of foam roll/tape

Yes, that's a sound (!) principle, but probably less important than making sure that all the corners, edges and joins are sealed.

And there's the floor. If you have noisy machines on the floor, consider putting them on OSB separated from the floor by something like fibreboard.

 

[MikeG.]

id share a link but unfortunately, I can't yet due to account age, but the idea behind it is the same idea as resilient channel, Sound can travel through the walls of the house via vibration on hard surfaces. The idea is to separate the new inner wall from the rest of the house essentially and by separating the two halves of the cleat with a layer of foam roll/tape

Well, with made-up details and homemade cleats I don't for a second think you can achieve what resilient channel achieves, and it will be at the cost of potentially difficult detailing and problems with junctions. Frankly, as I said before, I'd check with British Gypsum, and stick with their approved details.

 

[PAC1]

It is probably worth testing to find out how much of a problem you have first. If your fears are confirmed I agree with Mike that British Gypsum have invested millions in research to produce solutions to problems. Follow their advice.
You can get reasonable sound meters as free apps on your phone

 

[RobinBHM]

I wonder if plasterboard has the strength to be held just at the top.

And soundbloc is 43kg per sheet!

Also plasterboard is likely to curl after a while