Soundproofing. How to do it quickly & cheaply...

[BlardyBlaaaaa]

hi there

We will be moving into our new house at the end of March and are trying to do as much as we can before we move in. New bathroom and decorating, adding a few elec sockets, things like that. MY DH is adamant we need to sound proof the party wall in the 2 main bedrooms and sitting room.

I know very little about this, so asked a builder to quote. He suggested using 50mm celotex board in the alcoves around chimney breast (surely we need to do chimney breast too?) and plastering over the top.

The other suggested using special soundproofing material (applied to board, 25mm thickness) which is £1200 for materials alone, plus the price to fit it! Eek. I was hoping for it to amount to less than £1,000 in total.

Can anyone shed any light or tell me what's worked for you. Sadly it's beyond my husband's diy skills...

many thanks

Chimney breast walls are much thicker so don't need it. I agree with builder Celotex in alcoves. You can board over that and decorate on it no need to plaster? If you can afford to loose the space in the alcove, I'd suggest using thicker Celotex than 50mm. It comes in all thicknesses. Might be an idea to put some Rockwall down between the floor joists about a metre going from the party wall also.

I'm watching with interest as we moved into a 1930s semi last June. The party wall has piss poor soundproofing & the neighbours TV booms over our own. The bedroom is a nightmare it's like they are in our room watching tv. We are definitely planning on soundproofing but can't do the chimney breast due to a recess fireplace - just hope the alcoves will be enough

Just asked DH...
Build a false-stud wall fill it with sound deadening batts, then 2 layers of sound check board, should be able to be done for 2k BUT he said that is the extreme version and will be totally sound proof.
Celotex is a termail insulation and fab for that job BUT doesn't really sound proof although it may help.

Celotex is a thermal insulation

I agree

Filling all the gaps (including gappy unplastered brickwork unseen under the floor and above the ceiling) is needed, and use a dense, high-mass material to deaden sound (Celotex is very light). It is better to fix the studs and battens to floor and ceiling rather than to the wall.

You can get heavy mineral wool batts, they are much denser than the mineral wool used for loft insulation.

You can also get sound-reducing plasterboard, have not used it but perhaps it is extra-thick or extra-heavy.

Pack it between the floor joists and the ceiling joists by the party wall, but clean out and re-point gaps and cracks in the brickwork (it is very shoddily done where out of sight) preferably with mortar, but expanding foam is better than nothing, because noise will get through gaps.

thanks for all the advice.

Has anyone used acoustic board successfully?

Do I need to do over the fireplace too, or just the alcoves? And if we're thinking of building wardrobes in the alcoves in one of the bedrooms, is it still worth doing the sound proofing, or will a wardrobe full of (my) clothes have a similar effect?

thanks!

We have done one experimental room using Tutts method of the stud wall.
First we made sure that the floor boards did not touch the wall, cutting some away to form a gap along the partywall. We have used gallons of acoustic sealant everywhere.

The wood for the stud wall was placed on rubber strips that the lovely builders merchant gave us in sympathy to try. We used the strips along each edge iyswim.
We opted for Earthwool 50mm, 45kg, this is it's acoustic density, looks like loft insulation but much heavier and absorbs noise. Really easy to use, we manage to get 2 layers inside the stud partition.

Lastly 2 layers of acoustic plasterboard, Pigletjohn yes they were blimming heavy. The plan is now to plaster over and then build storage shelves for books and all our clutter will have a home, a small positive.

It has helped, voices are distant but all the sharp metallics, banging and flanking is still there. We have the added problem of suspended floors over cellars and the noise before was extreme. Our shared chimney seems to be acting like a weird speaker.

We should have gone for the 65kg Earthwool with hindsight. I reckon we've spent about £300 on materials so far excluding plastering. Also much cheaper going through the local builders merchant, a lot of the acoustic web sites charge for delivery of bulky items.

We'll start on the next bigger room after monitoring how effective this one is. Still very bitter to be building a stud wall over my beautiful newish plastered and f&b painted walls.

There are lots of modern wonder products out there and I spent weeks trying to demystify the science of sound and getting very confused.

You can do it yourself its not difficult.
we just looked online bought the stuff and did it one weekend.
My dh is a musician and we have done this in several studios over the years.
You need filling, baton, and plasterboard. I'm sure each one came in at less than £500 for materials.

"we're thinking of building wardrobes in the alcoves"

yes, that will also work. Preferably along the entire wall, floor to ceiling, and not fixed to the wall. If the wardrobes you choose are not that high, make some top-hinged doors for top-lockers where you can put your suitcases. You can use chipboard and paint or paper it to match the walls or ceiling.

Pack between the joists floor and ceiling as well using dense mineral wool batts..