Hi, anyone recommend suitable sound insulation to go in Ist floor
6inch joist void - kitchen below, w/proof plasterboard onto bottom of joists and w/resist chipfloorboarding on top. Bathroom above so looking for something w/proof and 2inchs thick, also I heard there is a product to lay between joist top and floorboard which cuts down mechanical noise transfer. Any info would be great.
A thin layer of sand. There are lots of other options too,
Sand won't last 5 minutes - once it's dried out, it 'drains' away like the sand in an egg timer, and it can't rest on the PB of the ceiling or it will cause sagging.
To the op: Rockwool cavity batts have decent soundproofing properties....can't fathom out why you want something waterproof though
really depends on the details. easily prevented though
'thin layer.' Thats all it takes.
There are two "types" of transfer of sound. One is direct via the the structure which, shall we say, one can call "impact" and the other being "air borne". There is only one characteristic that is significant in controlling the latter - that is mass. For the former it is appropriate to break up the transmission path. Other posts have, quite rightly, told about foam layers and new floating floors. The best product on this is that derived from aircraft but I cannot remember the name!
My suggestion is to to the following a) lift up all floor boards, put on battens or scotches in the side of the joists within the voids, bridge the gap with ply. (by all means put a rubber or foam or other interlayer between all such fixings). Calculate the load that the floor will take without any serious "duration of load" proportional creep in the joists (you will need to have some knowledge of timber engineering or get a building engineer to do it for you), fill the void with a suitable filler such as a sand cement screed or simply sand on its own to the appropriate depth likely to be no more than 40 mm
b) lay down sound deadening quilt (1/2" paper backed fibreglass) or if a modern equivalent foam exists better that) below the floor boards before relaying
Chris
the room below (if the original ceiling is high enough). i.e. insert a false ceiling not rigidly coupled to the joists above.
Robert
No they don't. They might help with very high frequencies but for most you need to add mass.
If the joists can take it, the normal way is to create 'coffins' between them to take the sand. It's a tried and tested method.
How far do you want to go with this? If you just want to deaden the noise to an acceptable level, it should be adequate to lay acoustic insulation batts between the joists, making sure to leave no gaps at the edges.
If you want to attenuate as much mechanical transfer as possible, then others have suggested methods of doing this, but it's a question of how much work you want to make for yourself, and what you're seeking to achieve.
Personally I wouldn't put sand on top of a plasterboard ceiling.
Cheers Richard
It would be nice to see some figures of just how much attenuation this would provide to the airborne path. At the various frequencies.
almost none at medium/low frequencies.
since the joists provide a perfectly good 'acoustic bridge'
We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Dave Plowman (News)" saying something like:
Victorian tenements had a 2" layer of clinker/slag chunks, resting on the lath and plaster. Certainly caused a great deal of mess when one ceiling fell down in my folks' house due to a leak upstairs.
I reckon rockwool batts seem ok, the sand option may be overkill for my situation. Thanks for help. Rog
By all means try rockwool. But don't expect it to work.
I've had a fair bit of experience of people trying to 'soundproof' sets for filming which have been built in an old factory, etc. Which is always on a flight path and noisy main road - usually in an industrial estate. And rockwool type stuff does near zero. Many seem to think heat insulation and sound proofing are the same. They're not.
Only thing that does work is to built the sets out of something more solid - layers of plasterboard being a cheap option.
Rockwool etc can help with room acoustics, though. But that's a different subject.
Rockwool can help by damping the resonance of the ceiling plasterboard. But that's really all it will do. It does make a difference, to an extent, but nothing magic.
Sand is easy to do, and you only need a few mm to damp plasterboard resonance. Its cheaper than rockwool.
Any of the suggestions given so far will help to varying degrees, but the theory behind them is in many cases not really as stated. How much NR do you need to achieve, and with what budget?
NT
so wool between the joists may stop me overhearing what theyre saying downstairs, but i''d still hear that there's talking go on?
is
We used to have noisy neighbours in our old terraced house and it wasn't the usual nocturnal sounds .. they used to giggle and laugh all the bloody time. Often wondered quite what it was they were dong;!....
The gaps between the joists can resonate at low frequencies like organ pipes. Rockwool will damp these resonances to some extent, but is not a miraculous cure for transmitted sound. Mass and stiffness will reduce transmitted sound. A combination plus isolation (floating floor os separate ceiling) will give best results. Making a soundproof structure is nigh impossible without going to bunker proportions, but a few dB can easily be achieved. The BR ADs used to give a few ideas. I think they can be found online somewhere.
tony sayer wibbled on Tuesday 13 July 2010 20:48
The correct method there is to either have a loud stereo pressed up against the wall or invite >10 people round.
After the random noises subside, generate a hearty round of applause.
:->>
Most would find a few dB reduction not worth the bother - especially as this is likely to be at higher frequencies if using rockwool, etc. Roughly 10dB would be the minimum most would want - a subjective halving of the noise.
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