New Home Owners And Snagging Forum

Advice on buying a brand new home => Snagging and defects => Topic started by: garfield on September 08, 2011, 10:34:08 pm

Title: Poor wall sound insulation
Post by: garfield on September 08, 2011, 10:34:08 pm
I moved into a new build flat 19 months ago I am having a complete nightmare experience with my neighbour next door with loud music, parties, foul language, arguments etc. Basically I hear everything even when he is talking at a low level or playing music at a low level it is as if he is my bedroom with me. The flat has been designed so that my bedroom backs onto his living room! I'm getting no sleep at all have been through mediation you name it i've done it. However he remains unreasonable. Ok that's my moan.. here goes the question:

The flat belongs to a housing association and they have offered me the opportunity to buy it. I am reluctant because I believe the party wall is not properly insulated. They development office sent me the sound insulation certificate which as you guessed it shows that it was sound tested according to so called 'building regulations.' Since all the flats only had a one year defect that year has elapsed therefore technically I am being told there is nothing I can do; I don't believe that and I am determined to take this further if need be for my own sanity. But I need help who do I go to? What do I do? Should I insist the housing association re test the sound?  Is there any law I could quote to them? Can I contact NHBC?

I don't want to cause any problems with the building company as I had lots of  snagging defect problems mostly minor and the contact who dealt with it was brilliant. But this partition wall is a major problem. I  have also been told that lots of party walls in new builds are not always inspected to insure the insulation has been done properly as there are just too many. Is that true? Please please can someone help?? Sorry this has been a long one :D
Title: Re: Poor wall sound insulation
Post by: Philofacts on September 09, 2011, 10:52:50 am
Sorry to hear of your problems.

First of all my advice would be DONT BUY THE FLAT  You would then be stuck with it and even if your neighbour moves out you could end up with another tenant neighbour from hell.  To have a bedroom on one side of a Party Wall and a lounge on the other is just poor design.

You ask whether you should contact the NHBC and you must do this as soon as possible. The Buildmark warranty is valid for two years. You should however, first write to the house builder and copy the letter to the Housing Association.  Don't worry about upsetting the builder, they caused this problem and your other defects! Hopefully they will be as helpful again.

It is good the flat was Acoustic tested, some of the builders hide behind the "Robust Details" for sound insulation and therefore do not have to have a test for sound insulation.  However the NHBC may decide that as it passed the test there is not a "defect" It will depend on where exactly the test was carried out.  I would strongly suggest that the Housing Association get the house builder to pay for another sound transfer test.  It would also be a good idea to look inside the cavity of the wall at your bedroom if it is masonry with a fibre optic camera.

Common reasons for sound transfer are:
Holes or gaps in the dividing wall, mortar joints, floors etc. 
Cavities not filled with mineral wool sound insulation at each end allowing flanking sound.
Wrong type of materials being used, wall ties, blocks, plasterboard.
Cavity bridged with mortar allowing sound waves to pass through.
Finishes and structure not isolated. ie other Robust Details not being followed.
If the Party Wall is Timber Frame then sound transfer may not be the only problem. It may not have the required fire resistance too if a layer of plasterboard has been missed or the incorrect plasterboard has been used.

Finally it is possible that the wall was not inspected or inspected properly/thoroughly.  There are not enough NHBC inspectors to make all the required inspections, so it is true the wall may not have been inspected.

I hope this helps but it will be down to you and your determination to keep complaining.

If all else fails there are laws to stop neighbours being noisy so you could contact your local council, buy be aware this could further antagonise your neighbour!
Title: Re: Poor wall sound insulation
Post by: garfield on September 09, 2011, 04:47:52 pm
 :) You are an absolute star! Thank you for your advice, you've answered a lot of questions for me that my housing association just haven't. Do you know I have done so much research on sound insulation and the way flats are built I think I need to change my profession :) in fact it is quite interesting actually.

I do need to pass something else by you or if anyone else can help out there.. The certificate that was given to me says it is a certificate of measured sound insulation of wall or floor calculating rating value 49dB dnT,w+ctr. Then as a side note it says walls in purpose built dwelling houses and flats airborne minimum value of DnT,w+Ctr=45dB. What on earth does this mean? I guess they are saying it meets the building regulations? But as mentioned surely this not the case since I can hear everything.

I'm not sure if I made it clear but the sound was tested between my bedroom to his living room.Also in a letter I received from the housing association they said that the sound test I had was an airborne sound test. What other tests are there. Your idea about a camera sounds like a brilliant idea. I would like to investigate which companies do this and how much it would cost if I did it alone. I am however going to suggest this to the housing association after they have replied to my last complaint. I look forward to receiving the answers to my questions.
Thanks so much again.
Title: Re: Poor wall sound insulation
Post by: Philofacts on September 10, 2011, 10:40:06 am
As far as I understand it (and I am not an accoustic engineer!)  the minimum insulation value required by the Building Regulations Part E is  is 45db for separating walls in purpose-built dwellings.

Your test value of 49db would appear to indicate that the insulation reduces the sound by 4db more than the requirement.  For floors and stairs the requirement is a maximum impact sound of 62db which must refer to transmittance not prevention!

The other accoustic tests that can be carried out are "impact" sound tests.

The NHBC will carry out the camera survey of the party wall as part of their investigation. Your house builder may also choose to do this to satisfy themselves they have built the wall to the required specification.

Have you informed  the housing association regarding your unsociable neighbour and perhaps his possible eviction? -  just a thought.

I found this website which may be useful to you Sound Insulation and Regulations (
Title: Re: Poor wall sound insulation
Post by: The Brickkicker on September 28, 2011, 06:00:23 pm
Since the industry has moved to light weight construction ...there are more and more complaints about noise transmission ...both across and vertically.

Laminate flooring doesnt help ?

The victorians could build houses and flats that did not transfer noise...why cant we?

The answer lies in cost and speed....essentially the same thing in construction these days ...and regulations that are just not stringent enough in the right places
Title: Re: Poor wall sound insulation
Post by: Philofacts on September 29, 2011, 02:26:30 pm
The Victorians didnt have Tv's and Hi fi.  They also didnt live above each other.

I agree standards are low and not being properly enforced.