Sounds and Smells

[Chomski]

Hello, I have two queries:

1. I live in a 1930s maisonette above a rather noisy family. There is no sound proofing between our floorboards and their ceiling. I've read that sand is a very good sound proofing material (roughly 1 cm depth laid on boards that are then attached to the joists of the suspended floor). Has anyone tried this and if so what success did they have and what sort of costs are involved - the room is roughly 4m x 3m.

1. Cooking smells from downstairs manage to find their way into our kitchen and airing cupboard via the pipes that run through both houses. What materials could be best used to cover the hole that the pipes go through - I'm presuming something that contains charcoal but am not familiar with particular products.

Regards, Mike

[BillR]

Filler foam

[John Armstrong]

Probably best to try to tackle item 2. first. If smells are getting through, air is being transferred. If air is getting through, sound will also get through.

[David Hemmings]

Be very carful about putting sand down, the weight can really add up, at the very least you will want a poroous membrane that will take the weight of the sand and transfer it ti the joists whilst not letting the sand get through.

Have you ever thought about filling up the entire void with sawdust ;)

sorry the last comment is only a flippant one, you dont want anything combustible in there.

Seriously though, a builder told me very recently on all new builds in the area one of the building inspectors was trying to force to use of some really heavy density rockwool looking material (normal rockwool is supposed to be reasonable sound insulating) into the voids to kill sound transmittance - and this was in an extenstion in a detatched house .........

Are you getting a full spectrum of sounds, high and low frequency ?

[Lee Blaver]

If the downstairs flat has a concrete ceiling, like our 1930s place, then pouring extra sand in is likely to make little difference. Neither is Rockwall, tried that also.

In our flat, most of the LF noise from downstairs is transmitted through the walls :(

Lee

[Michael Mcneil]

Foam every edge once you have taken the boards up then a loose layer of visquene & perhaps some glass wool under that. On the plastic sheet put some sand and then thicker boarding. It won't be as effective as moving or murder but it will cost a lot and be an upheaval.

[Fraser]

One of the (many) reasons I bought a hundred year old flat was being told that builders at the time didn't have skips, so the junk all went between the floors, making excellent sound proofing.

Nice to know that it could be a fire hazzard!!

F.

[Dave Plowman]

It has to be very dense material (and therefore heavy) to have any real effect at the airborne bass frequencies which tend to annoy the most.

[Chomski]

The full range of sounds are coming through, from the high pitch squeakings of their twelve year old child to the bass from the television (they appear to love any film with guns and helicopters). It can feel very intrusive. Is rockwool better than sand or of equal sound reducing properties (it would be a damn site easier to put in place considering it would not require fixing to the joists)?

[David Hemmings]

With a full range of sounds, looks like you should firstly follow the other advice given and block up any gaps that could allow air movement and hence the ease of noise transmittance.

You should (don't know with a shared property about have to) put some form of metal meshing in place first to stop the rockwool from falling in case of fire. i.e. to stop the further hazard of extra falling debris, which would be red hot rockwool.

Is it really because they are a VERY noisy neighbour, or is it because you have particularly poor noise insulation ? Have you talked to the neighbours about the noise either that they are creating or ask if they can easily hear you, or even if you could come in for a minute to hear the noise level ?

[Dave Plowman]

If it really is the full range of sounds coming through there must be some fair sized holes around, as even a normal ceiling and floor will attenuate the high frequencies considerably.

[The Natural Philosopher]

Rockwool is a complete waste of time.

First line of attack is to block all direct air paths, then remaining transmission is by structural vibration and resonances. You reduce that my increasing the mass, and increasing the damping. Sand is excellent in both respects. Look at car soundproofing. See any rockwool in a car? No. What you see is slabs of rubbery stuff applied to metal sheets to increase mass and add a bit of 'dullness' to the sound, plus dense fibre matting as well. Look under your car carpet.

Best practice is to sand fill in ceiling/floor void, lay down dense underlay and decent pile carpet, block up all pipe and duct runs between properties, double glaze and keep windows shut. Even so the bass tones will likely still come through.

[s]

[John Armstrong]

There is Rockwool and there is Rockwool. Stuffing roof insulation quilt rockwool wouldn't be much use, although I expect it would help a bit. RW6 would be a different matter. Accoustic data at

[The Natural Philosopher]

Fair enough. If you read the rest of the post you will see that cahracteristics of waht does work, described.

If that stuff has mass, it will be somewhat effective,

[Dave Plowman]

And use it on the house designer.

Noise is a peculiar thing. Perfectly normal household activities can annoy others in this type of house. I'd just mask the noise - if it's at normal hours - by turning up my radio a bit.