Assessing party wall sound insulation when buying

moneyistooshorttomention

Just checked and 60-65 decibels is "normal conversation level at 3 feet away" level.

So - depends on the buyer. Someone with poor hearing and/or a hatred of noiseless environments would be okay with that. I wouldnt be okay with that personally - as I basically expect no noise at all in my home.

Oxid8uk

lessonlearned wrote: »

New builds - max 62 decibels
Refurbs and conversions - max 64 decibels

Wooden floor - without sound insulation will produce approx 75 decibels

This is for impact noise only (through floors) and not applicable to sound insulation through the walls. There is no maximum noise 'limit' within a dwelling from airborne noise.

Ajoining dwellings built since 2000 need to meet the Building Regs Document E. This requires new builds to have an overall sound reduction of airborne noise of 45 dB through adjoining walls and floors, or for conversions a sound reduction of 42 dB. So, in simple terms, for a normal conversation at around 60 dB the sound insulation of the wall should make the conversation about 15 dB the other side of the wall, which is unlikely to be audible, depending on the background noise levels. It is actually a bit more complicated than this as the frequency sprectrum is assessed, with differing frequencies requiring different reduction values.

Pre-2000 there wasn't really any sound reduction requirements.

davidlizard

When you look at the house, go round and ask the neighbour about what the sound damping is like, and if he can hear some noise being made next door.

Most reasonable people would have no problem with this request. If he gets all moody about a simple request like this, ask yourself whether this is the sort of person you want to have as a neighbour?

abankerbutnotafatcat

Per Ognum (and coincidentally we also have an Edwardian Semi) I think it depends on the type of noise as well. We sometimes hear sneezes and on that basis our neighbours must get the worst of the deal as both the OH and me have allergies!

Davesnave

moneyistooshorttomention wrote: »

Just checked and 60-65 decibels is "normal conversation level at 3 feet away" level.

So - depends on the buyer. Someone with poor hearing and/or a hatred of noiseless environments would be okay with that. I wouldnt be okay with that personally - as I basically expect no noise at all in my home.

I think the literature is difficult to understand, but the values given relate to the reduction in sound levels expected, and this is further complicated by the fact that the decibel scale is logarithmic.

In other words, 64dB is not twice as loud as 32dB.

dtaylor84

Davesnave wrote: »

I think the literature is difficult to understand, but the values given relate to the reduction in sound levels expected, and this is further complicated by the fact that the decibel scale is logarithmic.

In other words, 64dB is not twice as loud as 32dB.

The logarithmic scale is used because 64dB is perceived as roughly twice as loud as 32dB. At least in theory. But you're right, it's exponentially more "power".

Oxid8uk

dtaylor84 wrote: »

The logarithmic scale is used because 64dB is perceived as roughly twice as loud as 32dB. At least in theory. But you're right, it's exponentially more "power".

Sorry but this is not correct.

In energy terms, a doubling of sound intensity is equivalent to an increase in the noise level of 3 dB. For example, two sound sources of 50 dB equates to an overall noise level of 53 dB. The human ear can only just detect this level of increase.

A 10 dB increase is perceived as the doubling of sound. Therefore 60 dB will be percieved to be twice as loud as 50 dB, 50 dB twice as loud as 40 dB etc etc.

And for clarity, the 62 dB given in the Building Regs 2000 (or 64 dB for material change of use) is for impact noise only. The noise level in the room below during an impact noise test should not exceed 62 dB. For airborne noise, the 45 dB is the level of reduction required, not the maximum noise level permitted.

dtaylor84

Ah, yes, you're right. I misremembered, then got the maths wrong too.

Oops.

Lumox75

We had some soundproofing work done a few years ago. I can offer you some advice, although it's been a few years so take it with a pinch of salt

Check whether the party wall is breezeblock or brick (get into the loft) - the latter is far more resilient to noise carrying.

Tap the party wall - if it sounds 'hollow' you may get issues with noise 'flanking'. The noise will bounce around within this gap and affect other rooms in the house, even if the noise on the neighbours side isn't being made in the opposing room.


From what I was told, the new sound regulations are essentially useless and our house (paper thin walls) would have probably passed anyway.


As always though, it comes down to how nice your potential neighbours are

reheat

societys_child wrote: »

http://www.youtube.com/watch?v=-5K3UdIiMpM

Test for sound proofing (slightly adult)
- need the sound up - listen carefully 23 seconds in

Hmm ... that fellah obviously has a pretty powerful effect on women!