Acoustic insulation thickness and wiring in studs

[junglejim]

Possibly a can of worms question but my internal studs are 89mm deep and we’re looking to use Rockwool rwa45 slabs. First question is thickness: local merchant stocks 50 and 100mm so was going to go 100 but now wondering how best to manage wiring ie to sockets and light switches within that?

 

 Many thanks

[Nickfromwales]

27 minutes ago, junglejim said:

Possibly a can of worms question but my internal studs are 89mm deep and we’re looking to use Rockwool rwa45 slabs. First question is thickness: local merchant stocks 50 and 100mm so was going to go 100 but now wondering how best to manage wiring ie to sockets and light switches within that?

 

 Many thanks

Don’t go 100mm as it will stop the boards going on!

 

Choose a better supplier and use 75mm with the gap then used for services. 

[Oz07]

50 I'd go with. Plenty room for services, I think the air gap actually helps acoustic performance and it will be cheaper too

[Thorfun]

We used 50mm and I think it was fine acoustically. 

 

it’s amazing how small 39mm space is for running cables (14.5mm either side of the insulation) depending on the size of the cable you’re not left with much before the boards. So can’t imagine how tight 75mm will be. 

[JohnMo]

50mm in the centre of the studs. The air gap make the whole wall perform better from noise perspective. And the wiring has somewhere to go

[Super_Paulie]

i used 50mm as the 75mm you can only get from insulation merchants really in bulk. Centre of the stud, plenty of room for pipe or cable drops. Its great stuff like has to be said, i love working with it in comparison to any other type of insulation. Cut slightly oversize with an old bread knife, whack it in and its self supporting. Easy to cut around boxes or reduce its thickness around services. It works a treat as well it really does.