party wall trad 9" / modern block-cavity comparison ?

[Simon]

Can anyone give some historical details of when/where etc. houses started to be built with cavities in party walls in British terrace/semi houses ?

Also, is a modern party wall much more sound proofing that the 9" brick ?

If so, this could be a factor in future home purchases. Unfortunately you cannot tell how well the wall has actually been built. Some of the

30s walls are very dodgy when you remove the plaster, since they were never intented to be seen.

I moved from a house with a quiet old person next door to a house with a family next door, both 1930s 9" party wall. It made me wonder how much noise we used to make for the old lady in the previous house ! Then banging on the stairs next to the party wall is most noticable, especially children running up and down.

I know in the 1930s people had less electronic noise, but surely they spoke just as loudly.

Thanks, Simon.

[Tony Bryer]

In my former BCO patch of New Malden, SW London, we did find a late Victorian cottage with cavity walls and flat iron ties, but most spec builders will still using 9" external walls throughout the 1930's. Party walls though were almost invariably

9". In my BCO days (1976-84) party walls were sometimes solid, sometimes cavity: both complied.

Workmanship has far more to do with it, also whether or not the wall is wet plastered.

I've told the story about the house built of 1/2 bricks. For a party wall the vital thing is that the mortar joints are properly filled so that there are no air leakage paths.

Check out the ODPM website for the current regs (tightened up because of perceived failings in this area)

[Simon]

I am sure a cavity party wall would cut down a lot of the impact noise on solid party walls - kitchen cabinets, fitted wardrobes, even joist movement noise. Also, noise from a TV next to the wall is transmitted by resonance of the wall at some frequencies - like high-bass booming.

This could be improved if both neighbours were doing a complete renovation. Also, the hardness of the bricks will make a lot of difference. But I suppose it is a balance of sound absoption and mass. I very hard brick wall could actually propogate more sound, despite being heavier. I wonder if some kind of injectable fluid could be invented that would make a brick wall more sound isolating ... and there goes the patent possibilities !

thing I heard - not from reading the regs myself, is that internal walls between e.g. bedrooms will have to have good isolation. This makes a joke of the cardboard partition walls in a lot of new houses upstairs. Will builders have to go back to much more solid internal walls ? This was one good thing about a lot of the older houses.

Simon.