Wall soundproofing

[rfn]

My sister & BiL live in a 70s semi-detached house. They have a lovely family next door who have three girls aged 1,5 and 7. The 5 & 7 year old share a bedroom which shares the conjoining wall with my sisters - and so even on a Sunday they are awoken when the kids wake up at circa 6/7am.

What's the best way of soundproofing this wall considering budget/effect achieved?

Thanks in advance....

[jules_s]

To effectively soundproof the party wall you need three things.

A dense object (the party wall)

A cavity

and a sound absorbing material.

Go have a look on the Lafarge website for case studies.

Flanking transmission may be harder to solve though...

[condor]

Cheapest way would be to cover the walls with cork tiles...cork side being face-attached to the wall to absorb the noise.

[cjs]

I have done it before. Used a 2"x2" stud partition, do not screw this to the wall, just the ceiling and floor. leave a 1/2" gap to the wall. Then fill with high density insulation and tack two layers of plasterboard over.

Works really well however you will lose 3" from your room size!

[Plotloss]

Depending on how far you want to go with it, we've got a product that has the same acoustic properties as 12 inches of concrete yet is a membrane a mere 6mm thick.

[ln1234]

I've been doing some research on this recently as we're doing a lot of work on our house and putting soundproofing in whilst we're at it.

From the research i've done:-

1. Screw battens onto the wall
2. Put acoustic foam/quilt in between battens
3. Affix Resilent Bars horizontally on battens
4. Affix 2 layers of acoustic plasterboard over battens with a 5mm gap around edges
5. Seal edges with acoustic sealant

Lots of articles online about this. Search for resilient bars on google.

[Plotloss]

Or

Stud
Affix Acoustiblok to the studs
Affix resi bar to the studs through the acoustiblok
Fix normal plasterboard to the resi-bar.

Done.

[ln1234]

Have you used Acoustiblok before? Whats it like compared to alternatives?

[Plotloss]

As far as I am aware acousticblok is the market leader and its astonishing.

They had a stand at the AV trade fair and they had a speaker going full tilt, to the point that it was painful to be near.

They dropped a tophat of 'blok on top of it and it was silent.

We use it to isolate screening rooms from background noise and its one of the only things that will allow us to get near NC15

We've just started dealing with a company that do a retrofit version that works in a similar way. Its only 'blok that do it in a 6mm thickness though.

[ln1234]

If you don't mind me asking, how much does the Acoustiblok stuff cost? Sorry OP - hopefully this is relevant to you too..

[rfn]

Thanks for all replies - really interesting stuff.

Would be interested on cost of that AB stuff too Plotless! .

[Goochie]

ln1234 said:

I've been doing some research on this recently as we're doing a lot of work on our house and putting soundproofing in whilst we're at it.

From the research i've done:-

1. Screw battens onto the wall
2. Put acoustic foam/quilt in between battens
3. Affix Resilent Bars horizontally on battens
4. Affix 2 layers of acoustic plasterboard over battens with a 5mm gap around edges
5. Seal edges with acoustic sealant

Lots of articles online about this. Search for resilient bars on google.

Use some "Green Glue" between the layers of plasterboard for additional soundproofing. Unlike the name suggests, its not actually a glue and never sets hard - it just creates a virbration absorbing squidgy bit between the boards. A google search should give you more info.

It cost me about £60 for enough to do a 4m x 2.5m wall - It comes in American sized tubes though so you'll need a larger sealant gun than a UK type. The Green Glue UK supplier can sorth you one of these too.

Doing the above gave us brilliant results but did reduce the room size by about 150mm. Insuating between the floor and ceiling below helped a lot as well.

[Dr_Rick]

Does all depend on the make-up of the party wall. Our sandstone semi has a single brick party wall for some reason. And no it hasn't been a single property that has been divided up. Our 'neighbours' are a right royal pain and insist on doing dodgy folk-music against the party wall. We've tried asking them to be more considerate but it didn't work. So soundproofing.

We got a local firm to fit studs fixed to the ceiling and floor (not to the wall), infill the studs with high density rockwool, overlay with 2 x layers of soundproof plasterboard and fill the edges with special sealant. Plaster and paint and we lost a total of 4in. The outcome wasn't as good as we were led to believe and it cost us a fortune. I'm aware of the lateral sound propagation and the fact that it's an old house with gaps all over the place doesn't help but I digress.

In the roof space we went freestyle. Chicken wire to provide a support for more high density rockwool, then two overlapping layers of edge sealed high density rolled matting. This stuff was seriously heavy. These were stapled to the joists. The aim being to minimise the sound going over the top of the aforementioned stud wall.

In one of the bedrooms that had already had the stud-set added (as above) we then added more. On top of the plasterboard we added two layers of maleable sticky-backed rolled matting. It was like high-density play-doh with a sticky back. And then another two layers of sound-proof board. Total loss I think was another 1.5in on top of the 4in loss from the first stud-set. This set up gave us a better result but resulted in a loss of original features and a need to redecorate the room a number of times.

Simple answer .... buy out next door!! It's a lot less hassle and doesn't give the blood pressure any problems.

Dr Rick.

[Goochie]

Dr_Rick said:

Does all depend on the make-up of the party wall. Our sandstone semi has a single brick party wall for some reason. And no it hasn't been a single property that has been divided up. Our 'neighbours' are a right royal pain and insist on doing dodgy folk-music against the party wall. We've tried asking them to be more considerate but it didn't work. So soundproofing.

We got a local firm to fit studs fixed to the ceiling and floor (not to the wall), infill the studs with high density rockwool, overlay with 2 x layers of soundproof plasterboard and fill the edges with special sealant. Plaster and paint and we lost a total of 4in. The outcome wasn't as good as we were led to believe and it cost us a fortune. I'm aware of the lateral sound propagation and the fact that it's an old house with gaps all over the place doesn't help but I digress.

In the roof space we went freestyle. Chicken wire to provide a support for more high density rockwool, then two overlapping layers of edge sealed high density rolled matting. This stuff was seriously heavy. These were stapled to the joists. The aim being to minimise the sound going over the top of the aforementioned stud wall.

In one of the bedrooms that had already had the stud-set added (as above) we then added more. On top of the plasterboard we added two layers of maleable sticky-backed rolled matting. It was like high-density play-doh with a sticky back. And then another two layers of sound-proof board. Total loss I think was another 1.5in on top of the 4in loss from the first stud-set. This set up gave us a better result but resulted in a loss of original features and a need to redecorate the room a number of times.

Simple answer .... buy out next door!! It's a lot less hassle and doesn't give the blood pressure any problems.

Dr Rick.

Your experience reflects ours in that we diddnt experience any dramatic loss of noise. What did give an improvement for us was insulating between the floor and ceiling (it was an upstairs bedroom we were soundproofing). For this is used high density insulation slabs that were left over from the insulation of the warehouse roof at work. Its about 1.5" thick and quite heavy.

What we suffer from now is the neighbour's new kitchen! They've now got cupboards along the party wall that they insist on slamming (sometimes at 2AM) and there is nothing we can do about the transmission of impact noise.

Simple answer .... only ever consider buying a detatched house!

[Dr_Rick]

Goochie said:

Dr_Rick said:

Stuff

Your experience reflects ours in that we diddnt experience any dramatic loss of noise. What did give an improvement for us was insulating between the floor and ceiling (it was an upstairs bedroom we were soundproofing). For this is used high density insulation slabs that were left over from the insulation of the warehouse roof at work. Its about 1.5" thick and quite heavy.

What we suffer from now is the neighbour's new kitchen! They've now got cupboards along the party wall that they insist on slamming (sometimes at 2AM) and there is nothing we can do about the transmission of impact noise.

Simple answer .... only ever consider buying a detatched house!

We're looking for a detached place at the minute. On the other hand, mini Dr Rick is due in November so retribution could be in the offing - Point ... Aim ... FIRE!!! 2am sounds like a plan, and we'll be awake at that point already so why not make the most of it.

Problem with the underfloor stuff, we've got original T&G vintage thick floor boards, lath & plaster ceilings, orignal cornice work and fly-ash insulation between the joists. And the electrics all run in metal tube conduits. I don't want to think about how difficult / messy it would be to open up the floors and fix things, AND replace the boards competently. Damn, after 3.5yrs we've only just finished redecorating since moving in.

Dr Rick (I feel your pain)