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How to Find Flanking Noise Before You Soundproof
If you are hearing your neighbours and thinking about soundproofing the party wall and the alcoves either side of the chimney, stop for a moment first. There is a simple test that tells you how to find flanking noise in your own home, and doing it before you spend anything could save you from wasting a large chunk of your budget.
The reason is flanking transmission, the noise that bypasses the party wall and reaches you through other connected surfaces instead. Treat only the obvious wall and you can still be left hearing the neighbours, so it pays to know exactly where the sound is getting in. Here is how Quietco finds out, and how you can too.
The Mistake That Wastes Money
The most common and most expensive mistake is treating only the separating party wall and the two alcoves beside the chimney breast. It feels like the obvious fix, but noise rarely comes through just those surfaces.
In a typical room, the sound is also flanking in through several other areas:
- The chimney stack, its fireback and the alcoves either side of it
- A perpendicular flanking wall, such as the wall you share with a dining room
- The window wall, which is an external wall but still carries noise as a flanking path
If any of those are letting sound through and you leave them untreated, you will keep hearing your neighbours no matter how good the work on the party wall is.
The Test You Can Do Right Now
This is the one time you will actually want your neighbours to be noisy. Wait for a moment when they are making their usual noise and your own house is quiet, then work through these steps:
- Put a finger firmly in one ear so it is airtight and you cannot hear anything through it.
- Press your other ear airtight against the wall you want to check.
- Listen for a few minutes, really concentrating on how much noise is coming down that wall.
- Move around the room and repeat on each surface in turn: the perpendicular flanking wall, the chimney stack, and the window wall.
- Closing the curtains while you test helps cut out other noise so you can focus on what is coming through the structure.
What the Test Tells You
The rule is simple: wherever you can clearly hear the noise, that surface needs treating as part of the job. If a flanking wall is alive with next door’s television and conversation, soundproofing everything except that wall will leave you disappointed.
Picture sitting on your sofa against a flanking wall, having treated only the alcoves. The neighbours make noise, and the wall your ear is closest to is carrying it straight to you, untouched. That is exactly the trap this test is designed to help you avoid.
Test Before You Spend a Penny
The whole point of the test is timing. Do it before you commit to anything, and you can make sure your soundproofing investment covers every path the noise is actually taking, not just the wall that looks like the culprit.
Get that right and every pound you spend is working. Get it wrong and you can treat half the problem and still be living with the noise. If you would rather have it assessed properly, a consultation does exactly this for you.
Fill out the contact form to book your FREE noise diagnosis call and we will pinpoint where your noise is coming from. Get in touch here.
How We Take It From Here
When we take on a project, checking every one of these paths is simply built into how we work. Finding the flanking areas is part of our four step method, alongside the main cause, the direct wall and the fixtures and fittings.
That is what makes the difference between a room that falls quiet and one that only improves a little. Do the test yourself first if you like, and when you are ready to treat what you have found, we can take it from there.
Fill out the contact form to book your FREE noise diagnosis call and take the first step towards a quieter home. Contact us here.
Frequently Asked Questions
How do I find flanking noise in my home?
Wait until the neighbours are noisy and your house is quiet, put a finger in one ear, and press your other ear airtight against each wall in turn. Wherever you can clearly hear the noise, that surface is a flanking path that needs treating.
What are the main flanking areas around a party wall?
Any wall running perpendicular to the party wall, including the window wall, and the ceiling and floor. Don’t forget the chimney stack and fire back too. All of these can carry noise around the party wall itself.
Why does treating only the party wall not work?
Because noise flanks around the wall through the connected surfaces. If you sit against an untreated flanking wall, it carries the neighbours’ noise straight to you no matter how good the party wall is.
Do I really need to do the test before soundproofing?
It is well worth it. The test shows you exactly which surfaces to treat, so your money goes on the paths that are genuinely letting noise in rather than being wasted on guesswork.
