Soundproofing between joists

[dave1814]

Hi,

I am about to put up a stud soundproofed wall in our semi-detached house, the room is located against the party wall. I am lead to believe that a lot of sound can travel across the joists as they run horizontally straight through into next doors. So I thought before I start work on the wall, should I try and stop the sound travelling under the floor.

My idea is on the (badly drawn) diagram.

Basically I was just going to cut out pieces of sound proof foam and put them in-between each joist (leaving a small air gap). Is this worth doing or won't it make the slightest bit of difference? Don't want to bother with trying to get the floor boards up if its not worth it. I was going to put down acoustic underlay anyway.

thanks!
Dave

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• dave1814
• 2 Nov 2014
• 1

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[footprints]

I doubt the joists run right through they most likely terminate a few inches into the wall. Unless you can isolate the joist from the wall (can't see a practical way to do that) noise will transmit through the wall anyway.

Stopping the noise getting into the joist in the first place is your best bet carpet / soundproofing etc.

 

[dave1814]

ah ok thanks for that.

Yes, I can't be sure about the joists, they probably do stop before the wall but haven't got the floorboards up yet to check!

I was thinking that investing in decent underlay might be the best / easiest option!