Q&A: Party Wall Soundproofing

I am writing this blog to try and shed light on a frequently asked question regarding noisy neighbours and sound coming through a party wall.

I reckon we see about 15-20 enquiries a week from the general public complaining about everyday noises from neighbouring properties. As Hush Acoustics pride themselves on being a company that is here to give information and solutions to all enquiries. I thought it would make sense to use one of these enquiries in a blog as these questions and answers are so frequently discussed.

Q: Is it possible to reduce sound pollution by only treating a party wall?

I received the following enquiry recently regarding noise transmitting through a party wall and general noises being an issue for this particular client:

“Hello,

I’m after some advice please. I am considering soundproofing due to new neighbours moving in. The noises we are experiencing are loud thudding whilst children are running on the wooden floor. We can also hear switches being plugged in so it’s not the kids fault, it’s just rubbish building materials.

I am more than happy to pay for soundproofing, my only concern is flanking noise. The party wall and internal walls are all breezeblock! Is it still possible to achieve a decent sound reduction by only treating the party wall?

Many thanks.”

A: Yes, however this will not remove the noise completely

My answer to the client, albeit not a clear cut one is listed below:

Thank you for your enquiry and sorry to hear you are experiencing these very common problems.

In answer to your question, yes you will see a reduction in noise transmission by treating the wall only. However, this will be a reduction only and will not remove noise issues completely. It is so important to point out from the outset that it is very difficult to make anything soundproof when you are trying to rectify an existing problem in an existing building, especially when you are only able to treat one part of the problem.

I recently published a quick blog on the incorrect use of the term soundproofing (read it here). If you only treat the wall you are only reducing the direct sound that will be passing through the wall itself. You correctly point out that there is also flanking paths for sound to travel. Direct sound reduction is exactly what it says on the tin. This is reducing the noise that is transferring directly through the problem construction. In this case it is the poor performing wall.

To reduce direct sound paths you simply treat the wall in question with a high performing wall lining system. Many can be found here.  Flanking noise reduction is a lot harder to treat as flanking noise transmission is basically any other path that sound will in-directly take to travel through the structure. This can be through the floors, ceilings, roof structures, beams, joists, internal walls or service penetrations. Flanking transmission is so hard to treat in an existing building.

We see this type of enquiry all the time where general noises are disrupting a client’s every day life. Simple noises such as speech, switches and sockets, footsteps, televisions, music and appliances are making life hell for neighbouring properties. This is quite simply down to the poor performance of separating constructions and mechanical connections.

Even if a separating wall construction meets the minimum requirements of the Building Regulations you will probably not prevent simple noises such as these from transferring from one property to another. Sound travels through materials so the more the two properties are connected the easier it will be for sound to transfer through the wall. This is the main reason why it is virtually impossible to soundproof an existing building, as you can’t break these structural connections.

We have created a consumer brochure that discusses acoustically treating the home (put the link to the consumer brochure when it is online). This mini brochure talks about treating all the walls, ceilings and floors within a property if you want to maximise noise reduction. However, I appreciate this can’t always be done. Therefore, a client normally wants to treat the problem area only, in this case the wall. This will probably satisfy the majority of situations as treating the wall can reduce the noise problem to a comfortable level. It is just imperative that any client realises that it will not cure the problem completely.

When it comes to a solution it will depend on the thickness of solution the client is prepared to have installed and what the existing structure is. In this particular case it is a masonry strucutre. Therefore I have we proposed two acoustic wall details for the client to discuss. HD1055 is an independent stud detail that is built away from the existing structure. This will achieve the better results for the reduction of sound as you are creating true separation from the existing structure to the new wall lining. However, the client will need to be able to afford to lose space within the room, as this treatment is quite a deep solution. If the client can’t afford a true independent solution then they are to look at the HD1041. This is a lot slimmer but is connected to the existing structure so won’t be as effective. A client will need to trade off performance if they can only afford to use a thinner solution due to room sizes.

Hush Acoustics are here to offer advice to all clients, whether domestic such as this to technical details for architects and high end multi occupancy residential developments.

Please contact us on 01519332026 to answer any question you may have.