Soundproofing dual occ

I have recently finished renovating an old house turning it into a dual occ and after the first w/e of two lots of tenants in I have two lots of irate tenants complaining about noise coming from the other unit.

I thought this may be an issue but not to the extent they are talking about.

There is currently just a standard 90mm stud wall between the two.

Does anyone have any ideas what the best way to sound proof would be?

Any ideas or thoughts (besides you should've done it properly in the first place) would be greatly appreciated!

Thanks

 

Gyprock has Soundchek : Gyprock Soundchek plasterboard - Gyprock
BUT I suspect you have bigger issues now you've done something obviously not approved and now tenanted.

 

Thanks @Propertunity
Have you used that before or have any idea if it's any good?

I don't believe I have bigger issues, it's essentially just two seperate tenants renting half a house each, it's just the sound that's currently an issue

 

An acoustic engineer would be the help you need. Typically a dual occ dividing wall is fire rated for occupant safety as well as noise and this isolates noise using separation and mass. Is this an approved structure ? Your site may be in breach of council regs and be uninsured. If a fire occurs you could face criminal charges.

There is no single magic bullet and a range of measures specific to the build are required. The first "x"decibels will be easy and thereafter the cost will escalate with diminished returns. A measurement of the problem is the start and a site assessment of the construction type and its problems. The leakage may be over wall, under floor and even transmitted through walls or around them. An acoustic consult would report the requires measures and their effectiveness v's cost.

 

Has this been approved by the council?

I would expect a fire wall??
Marg

 

Thanks for the replies, it is an approved structure, I probably wasn't very clear when I said Reno, it was essentially a cosmetic renovation with no structural changes.
I believe it had been rented in the past but obviously the noise hadn't been an issue to them.

I was thinking pulling the plaster off, sound proofing insulation then the sound proof gyprock may get me out of trouble but now I'm thinking it may require more...

 

Two layers of sound proof gyprock or use fyrcheck 16mm. I did half my house in fyrecheck coz i got it for free. and the 90mm wall filled with rokewall or acoutic insulation no gaps anywhere.

This is all cancelled out if there is a door anywhere beacusr the sound will go straight through as hollow or underneath the door gap.

 

Dont pull plaster off go over it with a layer off sound proof

 

Although u will need to pull it off to insulate wall. Or other option is make holes and get the insulation that sprays in like a foam and sets hard. But think its exxy

 

Glass is your friend

You can fill the stud wall with the thickest fibreglass batts you can get. Go for the highest R factor you can find. You've got to jam it in. Any airgaps will let sound travel though

But your problem will also be sound travelling across the ceiling so if the place is not insulated already now is a wonderful time to shove lots of big thick batts up there as well.

If there is a door, you've got to remove it.

 

Relying on history can be a trap - big difference between previously leased and approved dual occupancy.

The wall may be approved but the dual occupancy not.

 

I used it before putting 2 layers on each side of the stud work - so 4 x sheets thick totally. I also used fibreglass batts in the middle for sound absorption. Worked OK but some noise still traveled along the common floor.

 

Oh! The floor!!!

Please tell us it's concrete???

 

You're not going to like the answer to this @hammer
On stumps.....

The tenants were aware of the setup before moving in but obviously I need to improve it significantly from what it currently is....

 

Ahhh. Ok now you're in trouble.

The floor will still carry all of the sound no matter what you do to the wall and ceilings.

You either need to get an acoustic engineer in or reduce your rent/negotiate with your tenants/turn it into a single occupancy etc...

 

Cut the bearers/joists & resupport.

 

Why do u need an accoustic engineer? Sounds like a made up job if you ask me. Its really common sense. As for the floor put insulation underneath under the house.

 

The solution depends on the type of noise. Is it footsteps, voices, music etc.

However, don t use just any insulation in the wall, use Bradfords Soundscreen R2.5 for 90mm studs. Not that much more cost and worth every cent!

You can also use resilient plaster mounts for the plasterboard rather than screwing directly into the studs.

Put carpets with thick underlay in the rooms on each side of the wall if possible, too - as well as sound insulation under the floor between the joists if required.

Be aware, that there are two main types of sound and slightly different solutions for each.

If you can afford it, I suggest getting an expert's advice.

 

What are you doing about noise transfer above the ceilings?

 

A friend of mine, on a busy road, put sound batts in his ceiling, and then laid this really really heavy soundproofing sheet on top.