Sound transmission in 1930's semi

[liam_dens]

Do 1930 semi's have a cavity wall? My house seems well built and the party wall goes down below the floorboards. Our next door neighbours are elderly and when they are talking or listening to the radio the noise seems overly loud. I should add that we have knocked the downstairs rooms into one and we (and the neighbours) have open fires.

I suspect that the fires will be the weakspot, however we have just added some new hole-in-the-wall fires (one in each room) so blocking the holes wont be an option.

The recesses either side of the fires are only 14 inches deep so adding a framework and air-gap isn't really an option as we would loose the character of the place.

Im just suprised that the house being so solid appears to have this weakspot. Is it just typical of houses of that era and design?

[Tony Bryer]

I was a BCO in SW London for eight years: on my patch cavity walls did not come into general use until the end of the 1930's, a fact which horrified a colleague who came to us from Portsmouth where they had been the norm since WW1 - they were adopted not for insulation but to stop damp penetration: more of a problem at the coast of course.

The gotcha on some of our more cheaply built houses of this era was that they didn't have upstairs fireplaces and were therefore able to twist the flues into the thickness of the party wall, thus just leaving 1/2 brick deep chimney breasts upstairs and therefore only this much brickwork between the upstairs bedroom on one side and living room on the other.

[MatSav]

Mine does.

The recent "fashion" for laminate floors may have added something to the acoustic properties of either dwelling.

[Mark]

Not in the 2 1/2 bed design from 1931 on, I still own two of these, in fact my family built hundreds of these they were all cavity wall construction. Must have been some real cheep-skate builders on your patch.

-- Mark

[Andrew Gabriel]

Cavity walls go back before 1900 in some windswept coastal areas, and gradually work their way across the rest of the country over the following 40 or 50 years.

[steve.geach]

OK, how do I check I havew a cavity? Remove one brick from my party wall?

In fact what is a typical construction? full brick party wall/cavity/full brick party wall?

Thanks All

[liam_dens]

How do I tell if I have a cavity wall? Remove a brick from the party wall and check for an air space?

[bruce_phipps]

Good point. Carpet will tend to deaden sound. Also, the OP mentioned "knocking a wall down". But that is on the OP's side of the house --would it create more reverberation of noise from next door, I wonder?

Bruce

[liam_dens]

I suppose it sounds worse at the moment as we have the room totally stripped, walls are channelled for sockets and comms, bare boards and some fresh plaster.

Im planning on gluing a sheet of soundbloc or similar plasterboard onto the party wall with gripfill (pinkgrip better? non-slump?) recesses upstairs and down. It cant hurt. Floor will probably be new wood with a good underlay and rugs because the cat has the habit of coming in from the garden and chucking up. Dont fancy spanky new 1500+ pound carpet getting ruined within days!

Yes I know I should have an air gap, insulation, stud wall and two sheets of plasterboard but it will ruin the character of the room and I dont want to sacrifice the space.

[Tony Bryer]

Wates mainly. But where was your family building: problems of driving rain are far worse in coastal areas and as you go west, as compared with sheltered suburban London.

[Andrew Chesters]

When we talk of a cavity wall in relation to a semi, are we all talking about the party wall, or the other three?

I would expect the external walls to be cavity, but the party wall to be

9" brickwork for 30s houses. YMMV of course, depending on location etc.

Have I forgotten/missed something?

Andrew

[Mark]

LOL

Streatham, Clarence AV area Twickenham, Staines road area There were others in S-London but it was slightly before my time. To the OP measure the distance between front or back adjoining windows outside, deduct distance between window and wall your side add the same for next door, what you left with?

-- Mark

[Mark]

Yep a lot of Victorian houses on the south cost are built with a cavity but, IIRC only a small gap and no wall ties.

-- Mark

[MatSav]

Carringtons?