Soundproofing A Brick Party Wall-Best Method?

[macman81]

I have a brick built semi-detached house (solid walls not cavity) and want to soundproof a bedroom party wall due to noise coming through from next door. The approximate area is 8 sq metres. The wall is solid brick and plastered (not plasterboard). From researching this there seem to be 2 main options:
1) build an additional stud wall slightly out from the brick wall and use an acoustic insulation material in the stud wall, then plasterboard over. The problem with this is that it steals about 5-6 inches from the room size which I really can't afford to lose.
2) Use acoustic panels (Acousticel M20AD 20mm are the ones I've seen most commonly advertised), which are glued to the wall and then covered with 2 layers of 12.5mm plasterboard. This takes up no more than 2 inches of space, and is a lot cheaper too. I understand this is less effective than option 1), but the noise coming through is just general (TV, voices, walking on wooden floors, and not heavy bass etc), so this would seem to do the job and is my preferred option. Does anyone have any experience of installing/using these panels and are there any snags? Or other alternatives?
Typical price seems to be about £28 per sq m plus VAT.

 

[freddiemercurystwin]

I've just specified this note on a drawing to increase the sound insulation of a party wall;

PARTY WALL SOUNDPROOFING UPGRADE:
2 LAYERS OF GYPROC DURALINE FIXED TO BRITISH GYPSUM GYPLYNER UNIVERSAL METAL FRAMED WALL LINING SYSTEM TO GIVE 85mm CAVITY WITH 50mm ISOVER APR 1200 INSULATION INSTALLED IN THE CAVITY ALL IN ACCORDANCE WITH MANUFACTURERS INSTRUCTIONS

Have a look at the link below (diagram 5 page 236) for further details or give them a ring on their tech helpline, not sure about costs though, they would give you an idea I'm sure.

http://www.british-gypsum.bpb.co.uk/pdf/wb_glyner uni (walls)_08_06.pdf

Generally, as with everything in life, you get what you pay for.

 

[noseall]

I understand this is less effective than option 1),

not necessarily. a good architect told me that adding weight to any structural barrier will reduce noise travel effectively. the best soundproof booths are lined with lead.

apparently.

 

[Deluks]

Option 2 will be less effective, plus much more expensive. If you can afford it, go for it. You could always revert back to option 1 if it doesn't work, and sell the acousticel stuff on eBay. People will pay silly money for soundproofing products, even ones that don't work!

 

[macman81]

Thanks for the advice but sorry, I don't quite see how option 2) can be more expensive, I reckon the Acousticel will cost about £250 + VAT, the only other costs are 2 layers of plasterboard, adhesive, and mastic. Say £350 all in?
Surely building out a new stud wall plus the specialist acoustic fillings (2FT45 quilt, soundproofing mat and resilient bars) and plasterboard is going to be more than that, especially if the labour is taken into account?
I accept option 1) will give a better result, but I don't need absolute silence, just to remove some of the background noise transmitted. I'm not clear if the Acousticel and 2 layers of acoustic plasterboard (12.5mm Gypsum Soundbloc was what I was recommended) will do the job effectively or not?

 

[freddiemercurystwin]

Find out what the db reduction will be from the Acousticel supplier and then speak to British Gypsum using the link to find out theirs. They'll also be able to give you a greater understanding of sound reduction and what the figures mean. Sound reduction is a complicated subject. It kinda sounds like you've made your mind up already tbh.

1. You get what you pay for.
2. Sound is relative ie whats acceptable to you may not be to me and viceversa.
3. Attention to detail when constructing is very important in sound reduction so quality of workmanship should be second to none.

 

[AndyBill]

but wont the sound still come through the wall 'under the floor level' and 'above the ceiling' level?

 

[freddiemercurystwin]

but wont the sound still come through the wall 'under the floor level' and 'above the ceiling' level?

It cetainly will but you can take steps to reduce the noise coming through the wall itself.

 

[Deluks]

You don't need any special acoustic fixings. If you are attaching directly to the wall then yes, resilient bar will be used, but this is very cheap, providing you get it from a local builders merchant and not a specialist acoustic or soundproofing specialist as they always add a higher markup. The only other stuff needed will be rockwool slabs to fill the cavity. Again, relatively cheap from a local merchant.

If you don't want to use resilient bar then a simple timber stud wall spaced an inch from the existing wall will be adequate. Best only to fix it to floor and ceiling, and yes some sound will be transmitted via these points but overall you will cut down sound transmission massively.

I think best option will be to batten the walls with 2x2, add resilient bar horizontally, fill void with 60mm rockwool, fix plasterboard (2 layers of 12.5mm, staggered joints) and skim. Leave a gap of 5mm around the perimeter of the wall and fill this void with acoustic sealant.

Resibar MUST be installed correctly. See the manufacturers website.

6 sheets of 8x4 plasterboard
resilient bar
couple of tubes of acoustic sealant
couple of packs of rockwool (about 12 slabs)

Should cost little over £100 (and 4 inches). And will work.

 

[macman81]

Thanks for the advice Deluks. You say about 4 inches-If I use the resilient bar method, shouldn't the space loss be only about 3 inches (2 inch batten, plus 1 inch plasterboard)? Assuming I understand correctly, with this method I batten straight to the existing wall, rather than build a stud wall 1 inch out?
Using the Acousticel would have cost me about 2 inches, 3 inches I can certainly live with.
I'm not too concerned about noise transmitted through the ceiling and floor. The party wall is continuous up to the roof level and the floor (suspended timber) has a good thick carpet and underlay on it.

 

[Deluks]

Thanks for the advice Deluks. You say about 4 inches-If I use the resilient bar method, shouldn't the space loss be only about 3 inches (2 inch batten, plus 1 inch plasterboard)? Assuming I understand correctly, with this method I batten straight to the existing wall, rather than build a stud wall 1 inch out?
Using the Acousticel would have cost me about 2 inches, 3 inches I can certainly live with.
I'm not too concerned about noise transmitted through the ceiling and floor. The party wall is continuous up to the roof level and the floor (suspended timber) has a good thick carpet and underlay on it.

Well add in the resilient bar, which actually spaces the plasterboard slightly away from the batten, and why I suggested 60mm wool, and plaster skim (if indeed you do that) and that's another inch-ish.

 

[plumbamateur]

I did some sound insulation on my party wall a couple of years ago. I used 1 layer of Gyproc Soundbloc plasterboard (isolated from the party wall using small wood batons), followed by a layer of acoustic rubber matting pasted to the plasterboard (cant remember the make I'm afraid - but it is designed specifically for the purpose) - then another layer of the same plasterboard, topped with a plaster skim. It's worked really well against moderate volume music / TV etc, which was the problem. Good luck with which ever method you choose.

 

[Tozzy]

A friend of mine told me that sand is often used when dealing with transmission of sound through party walls. Apparently, you have to lift the floor boards from the room upstairs and lay the sand between the joints. I'm sure there is more to it than this so you'd have to read up about it to make sure it works. I've never tried it. Anyway, maybe something worth thinking about .

Have you tried telling the person on the other side of the wall to be more quiet?

 

[Deluks]

I know a guy who used sand in his home studio, he put up sheets of plywood against the wall and completely filled the void with sand. Worked apparently but I think the floor was solid. That's the problem with it, it's very heavy, gets everywhere and is still not as effective as a few layers of plasterboard. I would definitely not recommend using it upstairs

 

[Chowlo]

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