Sondproofing issue

[Dianne]

Hello,

I'm hoping someone can give us some advice.

We live in a semi detached house built in 1850. Up until recently we have had an extremely quiet neighbour but unfortunately we now have new neighbours who are not as quiet.

We don't want to move we have spent a fortune on our house and love it but we are hating hearing our neighbours.

We have had 2 quotes for soundproofing but both have said we'd get best results from building an independent wall but we absolutely don't want to lose space in our hallway or vestibule.

Here are the two proposals we have had so far

• Remove old wall
• Insert CLS timber stud frame work
• Insert 100mm slab acoustic insulation RW5
• Insert resiliant sound bars
• Apply Acoustic board 12.5mm double laired 25mm
• Apply fiberous tape
• Apply 2 coats PVA
• Apply bonding
• Apply 2 coats Multifinish
• Wet and Dry trowel to polish

OR

JCW Silentboard Plus 32.5mm x 1200mm x 1200mm (1.44m2) @ £68.99 + VAT x 16
JCW Adhesive @ £4.06 + VAT x 16
JCW Acoustic Sealant 310ml Tube £2.71 + Vat x 6
Acoustic Quilt 52mm x 600mm x 1200mm @ £49.44 + VAT x 4
Carriage @ £53.70 + VAT

I'd appreciate your views as to which option will give us the best result or can anyone suggest a better option.

We have 120 mm to work with between our plasterboard and the neighbours plasterboard.

Thanks, Dianne

 

[MikeG]

I'm not quite understanding this. It sounds as though you have a non-structural party wall, which would be a bit of a peculiar situation. Could you describe exactly what the wall is at the moment, please, working from one side to the other. Further, are the noises you are hearing air-borne (voices, TV etc), or is it banging and crashing?

 

[malcolm]

Good sealing and mass are the things to aim for. You can get rubber sheet that is thin and works well. Called heavy layer. Go for 10kg/m2 (5mm thick). Nail it to the wall with complete coverage and tape the panels together thoroughly then plasterboard over if rubber is not your look. Forget lightweight panels, they are for something slightly different. I am not quite sure what as mass is what you need. Plasterboard gives no soundproofing so have a listen before you plasterboard. If 10kg/m2 is not enough add another layer offset to go over the joints before you cover it over. I do this for a living in a field where I am sadly not allowed to use mass, but mass is the solve all thing for noise.

 

[Dianne]

Hi, thanks for the replies.

It's a stud partition wall which is between the 2 houses. Construction is 6" timber posts with lathe and plaster either side but nothing within the void.

Any advice much appreciated.

Dianne

 

[Dianne]

MikeG, the noises are a bit of both - banging and crashing, TV and hoovering!!

 

[MikeG]

Six inch posts, so this is oak framing? Oak framing which has been "modernised" (plasterboard), but wasn't insulated. Is the sole plate still there?

If I've got the construction right, then I would take off the plasterboard* on your side, fully fill the void with mineral wool cavity batts to a depth of 150mm, stuffing every little nook and cranny. Unlike insulating for thermal losses, you can afford to over-fill, so cut the insulation slightly oversize. Gaps are your enemy. Then, I would double tack: 2 layers of 15mm plasterboard with joints staggered, carefully filled all the way to the floor, walls and ceiling, and then fully skimmed (ie not just jointed). Then after decorating I'd hang a tapestry on the wall. Go upstairs and take a couple of floorboards up adjacent to the party wall, and stuff the depth of the floor with mineral wool out to the first joist away from the wall. Pay particular attention to service penetrations. Noise (through simple physics) seeks out nooks and crannies, and it is things like gaps under skirtings, around floors, and electric back-boxes which can be the biggest issue in trying to soundproof walls.

* In your first post you say it's plasterboard, but in this later one you say lath and plaster.

 

[Dianne]

Hi Malcolm, the rubber sheeting is for sale on Amazon and gets excellent reviews

We think we will fill the void between the posts with rock wool, fix a sheet of the rubber matting to the posts, add a layer of acoustic plasterboard, add another layer of rubber matting onto the plasterboard and then afinal layer of acoustic plasterboard.

Does that sound OK.

Thanks Dianne

 

[MikeG]

Hi Malcolm, the rubber sheeting is for sale on Amazon and gets excellent reviews

We think we will fill the void between the posts with rock wool, fix a sheet of the rubber matting to the posts, add a layer of acoustic plasterboard, add another layer of rubber matting onto the plasterboard and then afinal layer of acoustic plasterboard.

Does that sound OK.

Thanks Dianne

Sounds fine. Don't forget the floor void. And what happens in the roofspace?

 

[88v8]

As has been mentioned, be super-fussy about holes and gaps. A lot of noise can leak through a little gap.

A colleague of mine used to say that hell is other people.

Ivor

 

[Zebra]

A colleague of mine used to say that hell is other people.

Wasn't that Sartre?

 

[livias]

I want to reiterate that you should pay attention to the space under the floors. There is a rrasonable chance that there is NO barrier there

 

[Dianne]

HI Malcolm,

Do you think it would be beneficial to also use a proeduct called 'Green Glue' as well?

Thanks, Dianne

 

[malcolm]

Someone else might know about green glue. Good points about under floor and over ceilings too.

 

[Dianne]

HI, yes hopefully someone will know more about Green Glue!

 

[MikeG]

I'd be a little careful of Green Glue in a period property. If you keep it's uses to entirely modern materials, then fine, but I really wouldn't have it come in contact with any historical element. It's like a low modulus silicon, and who knows what that would do to ancient timbers, or to soft red bricks, and so on, over decades and more.

Frankly, there is a danger that you could be over-focusing on the sound-proofing materials, and under-focusing on the details. It is far more important that you deal with floors, ceilings, junctions, services, loft space and so on, than that you have some rubber or specially expensive sealant. I'm an architect. I have had to deal with the soundproofing of all sorts of buildings including tiny modern flats in lightweight blocks, and I can tell you from bitter experience that specifying the very best and latest in soundproofing materials and techniques can be completely undermined by a bricklayer not fully filling all perps, or electricians (against instructions) fitting sockets back-to-back, or by poorly fitted insulation, or incorrectly fitted floor joists, or poor workmanship around windows. This is not a job that you turn over to just anybody. You need to see that the workmanship is of the highest order, because good workmanship with ordinary materials will give you a far better result than poor workmanship with the latest whizz-bang product.

 

[Dianne]

Hi Malcolm, before we go ahead and purchase materials for soundproofing our party wall. I heard about using a product called Genie Clips.

Ever heard of them?

<https://www.soundstop.co.uk/solutions/wall_solutions/Genieclipwall.php>

Dianne

 

[MikeG]

It's almost as though I'm not posting in this thread........

 

[a twig]

It's almost as though I'm not posting in this thread........

Did someone say something? :lol:

 

[MatthewC]

Dianne

I think you really should at least consider what Mike is saying (and possibly answer his questions) before you make your decision about this. He is a professional in this field and knows his stuff, and his advice is given for nothing on this forum.

For my part, I would say that are many principles that we all seem to work by, sometimes without really spelling them out. One of these which I will spell out is that you never want to do irreversible tasks on an old building in too much of a hurry without VERY careful thought, as you can't undo it. In the same way, there are jobs that you only want to do once due to the hassle or the cost, so the same principle applies. A second principle is that (very often and for a variety of reasons) new materials do not mix well with older ones, and so we are all quite cautious about using some new-fangled invention without good justification; sadly, the overwhelming majority of professional builders don't care about this sort of consideration - by the time a problem makes itself known, they are long gone.

So you have to weigh the options and make your own decision about what to do - it's your house, after all - but most of us here want to take the long-term view which is to be sympathetic to your house.

Just saying!

Best of luck

Matthew