Sound proof party wall

Well it won’t do any harm and then you can re-evaluate to see whether anything more needs doing. I would be generous in applying, any slight hole that’s missed will continue to leak sound.
What is above, below and to the sides of the wall? I had floorboards when left large gaps into next door under the wall which was a right pain.
 
I've had the soundproofing in livingroom for around a month now and it's been unreal. I haven't heard a single noise from next door. We still have upstairs to do but expect similar results.
 
I've had the soundproofing in livingroom for around a month now and it's been unreal. I haven't heard a single noise from next door. We still have upstairs to do but expect similar results.
Can you just confirm the method you used in the living room?
 
Hi, I’m new to the forum but thought I’d comment to see if it helps you in any way.

Firstly as you said expanding foam isn’t the best for soundproofing as it’s not dense, if you can use cement, for deeper holes use a mortar gun to squeeze the cement in.

We got a builder to cement render the internal walls to make them airtight and level but this isn’t a major issue if you don’t 👍

We then built a stud frame using (4x2) and used a rubber strip on the outside to ensure it’s not directly touching joists/walls. If you can, don’t directly fit the frame to any walls especially the party wall, fix it to the floor + ceiling joists.

We researched lots of companies for the clips/bars and found they all pretty much have the same reviews/data but we opted for genie clips and bars as they were miles cheaper.

1st layer of 15mm acoustic plasterboard leaving a 5mm gap around the edges for the acoustic sealant (ac50), layer of tecsound sy100 on top of this, 2nd layer of 15mm acoustic plasterboard again leaving 5mm around the perimeter.

Also you may also want to make note about electrical sockets, you can either buy socket putty pads or an acoustic electrical box, both will help with airborne sound.

One last thing, radiators or TV’s, use extra furring bars/clips for these and don’t fix into the studwork. A lot of people underestimate these weak points and still have issues with sound not knowing these little things.
 
I've had the direct to wall soundproofing in for a decent period of time and it's been absolutely superb. Really haven't heard a peep since we had it installed.

The system we used was DIY (I had tradesmen family members fit it for me). At the time I wondered if I needed any formal permissions before starting. A number of tradesmen mates were adamant I didn't and I also couldn't see any confirmation online. Does anyone know for sure?

To summarise, I used a direct to wall soundproofing kit (furring channels drilled to the brick with plasterboard attached). I removed the old dot and dabbed plasterboard beforehand. I'm based in Edinburgh and understand the party wall laws differ from England and Wales. The house is a 1970s, 3 bedroom, semi detached.

Should I have got permission before I started or am I good?
 
Hi All. I've read some great advice on this forum with regards to sound proofing, so wondered if I could get some advice on my own project before buying material.

I have recently moved into a semi detached house and found that the soundproofing on the party wall is pretty bad. We can hear muffled conversations from next door and when I put my ear to the wall, I can make out exact words (not that I am in the habit of doing that of course)! This impacts the ground floor living room and two upstairs bedrooms.

The construction of the existing party wall is dot and dab plasterboard over two layers of brick with a cavity in between the brickwork and presumably dot and dab plasterboard on the neighbour’s side.

We have already done some work in one of the bedrooms (and have made some mistakes). We removed the dot and dab plasterboard and built a 2"x"2 stud frame approximately 15mm away from the brick. We also lifted up the flooring and filled any gaps on the joists and on the brick wall with expanding foam. We then filled the stud frame with acoustic rockwool (trying to maintain an airgap) and then sheeted with one layer of acoustic plasterboard. We then plastered over the top. We did use some expanding foam in a few points on the brick wall behind the stud frame to stop the bounce in the wall. I now know that wasn't a good move. :S

After the work was completed, we later found that we could still hear voices in the upstairs bedroom that I suspect was emanating from the neighbours’ downstairs living room. Sound must bounce up the party wall. I’m hoping that this will be improved when we repeat the soundproofing process in the other bedroom and living room as there will be more holes/gaps in the brick wall that we can cover up.

I now want to make some improvements for the sound proofed walls in the other two rooms. My proposal is:

  • Remove dot and dab plasterboard
  • Fill any holes in brick wall or on joists in the floor with cement (rather than expanding foam)
  • Build a stud frame 15mm away from the brick wall but use 3"x 2" instead of 2"x 2". Also put some rubber strips on the sides of the stud frame that is in contact with the floor, ceiling and side walls.
  • Fill stud frame with a denser and thicker rockwool this time (75mm with 60kg density rather than 50mm with 45kg density).
  • Sheet with acoustic plasterboard
  • Add tecsound 50 over the plasterboard
  • Sheet with another layer of acoustic plasterboard
  • Plaster wall

I've reached out to soundproofing companies and they have all suggested that using a resilient clip system on top of the new stud frame would be worthwhile but that takes the cost of materials to more than I want to pay. Is it really required if we are building a new wall? Does my proposed build sound reasonable? At this stage I just need to block the muffled voices from entering my house.

The wall in the living room is approx. 7.5m by 2.4 and the bedroom walls are 3.6m by 2.3m

I am a complete amateur, so any advice is greatly received.
I have a fair amount of experience with this - and there is a great deal of information online that wasn't there pre-pandemic - more people working from home. My issue was similar, but worse, tremendous sound transmission through the party wall. I opened the wall to try to determine the issue, as we specified a j-channel installation in the new construction with an extra sheet of drywall. The j-channel was installed incorrectly, [drywall - stud - air gap - stud- drywall - j-channel - stud]. This error created a triple-leaf wall, which actually increases sound attenuation. So avoid the resilient clip system; it will similarly create a "triple-leaf wall". Instead, add mass to the existing wall, with additional drywall overtop the current wall. I stripped out the j-channel and laid two sheets of 5/8 drywall with "Green Glue". This created a 2-leaf wall, more mass and also the properties of the Green Glue. The new wall structure was [drywall - stud-airgap - stud -drywall, green glue -drywall-green glue - drywall] This worked so well, and I don't hear anything between the party wall. It is also relatively easy to do - you just need a drywaller, to hang, tape, mud and sand the walls. Basic drywall skills. Good luck. Caveat - this is based on wood or steel stud wall construction. Concrete walls suggestions are to "decouple" the mass first, but the principle of two leaf system still is applicable, based on what I read. Check "STC ratings of wall structures" - some great online information.
 
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I've had the direct to wall soundproofing in for a decent period of time and it's been absolutely superb. Really haven't heard a peep since we had it installed.

The system we used was DIY (I had tradesmen family members fit it for me). At the time I wondered if I needed any formal permissions before starting. A number of tradesmen mates were adamant I didn't and I also couldn't see any confirmation online. Does anyone know for sure?

To summarise, I used a direct to wall soundproofing kit (furring channels drilled to the brick with plasterboard attached). I removed the old dot and dabbed plasterboard beforehand. I'm based in Edinburgh and understand the party wall laws differ from England and Wales. The house is a 1970s, 3 bedroom, semi detached.

Should I have got permission before I started or am I good?
Hi Georgie Boy

I know this thread is quite old now but if you’re still around I was wondering if the ReductoClip direct to wall worked well for your bedrooms as well? I’m in same position and going to use soundproofing store to get the clips for front room and bedrooms. The walls are leaking so much noise through from next door :(
Thanks
 

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