Sound Deadening Underlay

[Jeff Gaines]

I live in a flat, converted from a large house in 1960 or so, with no sound deadening between ceilings and floors.

I have agreed with my upstairs neighbour that we will investigate the possibility of sound deadening underlay.

Does anybody have any experience of whether or not this stuff works and how effective it is?

There's loads of them around in thicknesses of 3 mm to 18 mm and they all claim to be effective but are they really?

Main issue is impact noise although I can hear some speech through the floor as well.

Thanks.

[NT]

Prety much any underlay is sound deadening, but you'll need to do far more than that to get a decent result

[Dave Plowman (News)]

If it is footsteps on a hard floor you're hearing, any underlay and therefore carpet will stop this. As you are eliminating the source of the noise. Rather the same as turning off a radio. Trying to block actual noise is rather more complicated.

[The Natural Philosopher]

a bit. It does a bit. If there are bare woood or tiled flors above, it turns the clonks into thumps, that's all. If there is carpet, with underlay, it does the square root of f*ck all.

It will for sure help impact noise.

But the key thing for reducing transmission is mass damping and airtightness

so making sire the ceiling is airtight and covering it with the sort of heavy rubbery gooey plastic stuff used to soundproof cars, is a lot better. Or using sand bewteen floors to fill voids.

[dom]

Read Part E of the Building Regulations Approved Documents:

lots of well-proven practical advice on soundproofing.

[A.Clews]

Thus spake "Dave Plowman (News)" ( [e-mail]) unto the assembled multitudes:

I beg to differ. It'll certainly help, but it won't stop it. You'll still be able to hear people moving about. And it won't make a lot of difference to airborn sounds. In the 1980s I lived in a flat which was probably like the OP's and despite thick underlay and thick carpet, I could still hear the neighbours changing their minds.

I guess it depends how noise-tolerant the neighbouring occupiers are. It really got me down. After two years I bought a house and saved my sanity!

[The Natural Philosopher]

golly. Good thing my house was built before that lot! Id have had to have built a new celing over my exposed beam ones!

Anyway, yes, thumbs up to that. Looks lie adding extra plasterboarrd is more useful than anything.

[Dave Plowman (News)]

multitudes:

Well, yes. But it will reduce footsteps to near zero.

Never said it would. Although good underlay and a thick carpet will help slightly over either a bare floor or a hard covering.

Sounds like you had other problems there.

Indeed. There should perhaps be noise separation measurements as part of a survey for flats

[Dave Plowman (News)]

I've been saying that for ages. It's the easiest and most cost effective way.

[The Natural Philosopher]

multitudes:

IME not near zero. In our parlance it puts an estimated 12db/octave low pass filter on them, which does not a lot sub 100hz, quite a bit uop to

800hz, and almost completely removes any higher harmonics :-)

[Jeff Gaines]

I've got a quote for:

• Fix a suspended ceiling

• Fill ceiling void with 100mm Acoustic Soundslab

• Line ceiling with 2 layers of 12.5mm SounDbloc board

• Plaster skim finish

Perhaps that's a better solution. It's not possible on all the ceilings as some are highly decorative but it can be done in the bedroom.

[A.Clews]

Thus spake The Natural Philosopher ( [e-mail]) unto the assembled multitudes:

Strangely, I never thought of the problem in those terms. I just used to say, "F*cking hell, the herd of elephants is on the move again." :-)

[The Natural Philosopher]

multitudes:

I am bloody surprised mate!

thunder is after all merely a spike wots been rolled off massively above a few tens of hertz, and passed through natures own reverb system :-)

I just used to

The thunder of massive hooves as against the patter of tiny feet..

Its all in yer spectrum innit?

I designed something I called a 'whisper filter' once. 18dB/octave peaking high pass centred around IIRC 5Khz. The idea was to increase Tannoy intelligibility in reverberant places like railway stations. Being as how the lower the frequency the more it flops around. High frequency sibilants have plenty of intelligibility, but decay fast, reducing perception of delays from distant speakers and reverberation stuff.

Bench test were promising, but it never got taken up..

Strangely, its pretty much what my wife's hearing aid is set to...