Cavity Wall Issues

bluecatface

Recently we purchased a second hand house, we got a great discount so were happy. However after living in the house for quite some time a sound issue has developed.

Now we decided we would solve it. let me share with you what I'm talking about. Our wall is joined to our neighbours wall.

It consists of plaster board, that has a 50mm or 2 inch polystyrene backing. This board is stuck on by some glue to the 100mm or 4 inch concrete block, then behind is a cavity of two inches and then our neighbours wall, which consists of the same a 4 inch block and a two inch polystyrene plasterboard taped and jointed.

Now, for a while sound has been an issue, but very light, but enough to wake me up in the morning Doors, light chatter, chairs moving.

So I called in the Engineer responsible for the project and he advised me in his best engineering face, that the best solution was polybead, so I contacted various polybead companies around Ireland and they all informed me that polybead has no stc or sound insulating qualities.

Then I decided to call a friend because I read about rockwool etc and was going to build a stud wall and would need to move the sockets away from the wall.

The thing that happened next was bizarre to say the least. We took the socket covers off the wall to discover that they had been chased into the blockwork. So let me re-cap the four inch wall had been reduced to 2 inches in places behind the plasterboard.

Needless to say I am sided by friendly neighbours and they allowed me to inspect their sockets and low and behold same thing, chased two inches into the solid blockwork.

Regarding the law for 1997, In part E regarding sound transmission I was led to believe that cavity wall has to meet a certain requirement. Can anyone clarify this ?

My question is this has the builder in anyway broken the law ? In that the brick is only 2 inches at places plus cavity plus in places 2 inches of neighbours house.

I rang the engineer and he played dumb, but also stated that the sound would'nt travel easier through a two inch than a four inch. I find that hard to believe because mass blocks sound, not misinformed statements.

He did state however, that a hole in the blockwork would allow sound to pass. How do you find a hole in a cavity wall without damaging it.

I have repaired our side of the wall, and the neightbours are willing, but is there an easier way to find out if the cavity wall on there side has been breached.

The irony of the situation is oue neighbours don't hear us at all.

Experts please advise.

sinnerboy

Move the sockets off the party wall . Fill the voids in the blocks to restore the full 100mm thickness

Ask your neighbor to do the same

bluecatface

Is there any way to find where the weaknesses are, without having to dfo them all?

Slig

There is equiptment out there to measure sound, as far as I know the experts can direct you to the areas that are causing trouble. Trying to sue the builder will probably get you nowhere, maybe check your home insurance though.

Stuxnet

that wall the party wall its called, should of been built what we call on the flat, you have presumably 4 inch block 4 inch cavity containing 2 inch insulation 4 inch block again, those blocks should be laid on their sides giving you a 9 inch wall with no cavaties, a better job for sound/fire insulation, thats the way i've seen them built, 12 years as a carpenter

davidoco

helpinghand wrote: »

The irony of the situation is oue neighbours don't hear us at all.

Funny that. Are they thinking by saying that, that the issue is on your side and they have no need to carry out any works?

From my own experience with plasterboard bonded to party wall a satisfactory solution was to remove the plasterboard, skim wall, fit battens with acoustic barrier, 50mm fiberglass and double dry lined.

Carlow52

1: How did u find out that it is 4-2-4?

2: how old is house?

What direction are ceiling joists running?
they could be seated in party wall.

if the 4-2-4 was sealed properly u should not get much noise so there is a hole somewhere.
What about attic?

yellowfever

Davidoco,

Thanks for the response, what you have suggested is what we plan to do. Render wall, Battens 50mm with Rockwool, and as an extreme measure soundblock, because were taking off the old plasted board we´ll hardly loose any floor space.
Great response, appreciated.

As for the neighbours house, they are more than keen to help us out.

Carlow52, you raise some interesing questions which I can´t answer at the moment. I will however find out.

Some I can, the house was built in 2001, and secondly the engineer gave me the plans and informed me about the structure type.

And I checked it is 4 inch on edge.

As for the joists, I can find out, and as for the attic, I´ll look into it.

Carlow52 and Davidoco Thank you both.

davidoco

localsurf wrote: »

.............. we plan to do. Render wall, Battens 50mm with Rockwool, and as an extreme measure soundblock, .

good idea to use a insulating strip between the batten and the wall. Something like this would do just fine http://www.soundservice.co.uk/acoustic_sealing_tape.htm

These bars are also a good idea (I couldn't get any handy at the time) http://www.soundservice.co.uk/resilientbar.htm