How Much Does Soundproofing Reduce Noise?
Our homeowners here lived in a 1950s semi and could hear a great deal through the shared party wall, the neighbours’ TV, conversation and music, plus impact noise from a bedroom diagonally above where the children ran around. It raised their blood pressure, left them stressed, and had them seriously thinking about moving. So how much does soundproofing reduce noise, and was it worth them staying and fixing it?
The honest answer, when the job is done properly, is that we typically achieve around 80% perceived reduction in airborne noise and about 65% in impact noise. Those are figures based on how we perceive loudness, which is why Quietco measures results the way a person actually experiences them, not just on paper.
Why a Slim Panel Is a Waste of Money
Before we go further, a warning. Sticking a slim panel or clip system to the alcoves either side of the chimney, the quick fix so many suppliers sell, is largely a waste of money, and this project shows why.
That approach ignores the causes that are actually making the noise worse, skips most of the real direct noise path, and does nothing about the paths noise takes around the wall. You can spend a lot on a product like that and still hear your neighbours, because the noise simply is not coming through the part you treated.
And it is not only slim panels that fall short. Even treating the entire direct noise path on its own will not get you there, because without also fixing the main causes and the flanking paths, the noise just keeps finding its way around the work you have done.
First, the Main Causes
Before any soundproofing goes on, we deal with the main causes, the faults that make everything else pointless until they are fixed. In this house there were three:
- Dot and dab plasterboard on the chimney stack, which amplifies the noise through its hollow voids and even channels sound down from the room above
- Holes in the structure, common in older homes as decades of footsteps loosen the sand and cement around the joists, and a likely culprit whenever you can clearly make out a neighbour’s TV or phone call
- The suspended floor void, which behaves like a giant drum passing noise between the two homes
These are what we mean by main causes, and dealing with them is part of our four step method. No wall system, however thick, will work until they are sorted.
The Direct Noise Path Is More Than the Alcoves
The direct noise path is not just the two alcoves. It also includes the chimney stack, the fire back behind where a fire sits, the area above the ceiling and the area below the floor, all of which have to be treated and tucked together so there are no gaps.
There is also one step almost everyone skips. The wall is resonating like a ringing drum, so we sound deaden it first, because if you simply build a frame in front of a resonating wall, that trapped sound just channels off into the floor, ceiling or flanking walls instead.
Only then do we build a fully isolated, decoupled floating frame in front of it. This is the difference between a two day job on the alcoves and the proper week or more that real soundproofing takes.
The More Flanking Paths You Treat, the Quieter It Gets
Here is the honest part about budget. The more indirect, flanking paths you treat, the more noise you remove, and this couple had a set amount they wanted to spend. So we treated the main causes, the direct path, and a couple of key indirect paths, the ceiling and the suspended floor void.
If they had wanted an even bigger reduction, there was more we could have done. The other flanking paths worth treating in a room like this are:
- The window wall, either up to the first reveal or across the whole wall
- The wall shared with the dining room, which runs off the chimney breast
- A decoupled ceiling on a resilient system, which is especially good for cutting impact noise from above
That is the beauty of the method: you can scale it to your budget and still get a meaningful result, then do more later if you want.
The Details That Protect It All
The final step is the fixtures and fittings, and it is where a lot of good work gets undone. On this project the new floorboards were decoupled from every wall in the room, the skirting was isolated so it could not bridge the floor and wall, and the sockets were sealed airtight at every layer rather than left as a hole with a putty pad over it.
Get these small details wrong and you can compromise everything behind them. Get them right and they lock in the result.
So, How Much Quieter?
So, back to the question. With the full four step method followed, this kind of project delivers roughly 80% perceived reduction in airborne noise and around 65% in impact noise, and the couple could finally relax in their lounge and watch their own TV without the neighbours’ coming through it.
The most important thing to understand is where that result comes from. It is not mainly the fancy materials, it is going the extra mile, opening up the ceiling and floor, treating the fire back, and fixing the main causes, that does the heavy lifting.
Fill out the contact form to book your FREE noise diagnosis call and find out how much quieter your home could be. Get in touch here.
Frequently Asked Questions
How much does soundproofing reduce noise?
Done properly with the full four step method, we typically achieve around 80% perceived reduction in airborne noise, such as TV and conversation, and about 65% in impact noise, such as footsteps from above.
Will a slim soundproofing panel fix my noise problem?
Usually not. A slim panel on the alcoves ignores the main causes, most of the direct noise path and the flanking paths, so you can spend a lot and still hear the neighbours.
What are main causes and why do they matter?
Main causes are faults in the building, like dot and dab plasterboard, holes in the structure, or a suspended floor void, that let so much noise through that no wall system works until they are fixed.
Can soundproofing remove impact noise from upstairs?
It can significantly reduce it. Impact noise, like footsteps and children running, is harder to treat than airborne noise, but decoupling the ceiling and treating the structure makes a real difference.
Can I soundproof to a limited budget?
Yes. Because the more paths you treat the quieter it gets, the work can be scaled to your budget, starting with the main causes and the direct path and adding more later.
