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What the Homeowners Were Dealing With
If you are trying to figure out how to soundproof a bedroom in a semi-detached house, this is a real case study of exactly that. A 1930s semi where the owners could hear clear conversation, make out individual words, and worst of all, hear the neighbour’s TV while trying to sleep.
The noise was coming from two places: the neighbour’s bedroom on the other side of the shared party wall, and their front living room diagonally below the bedroom. They just wanted to sleep without being disturbed and speak normally in their own home without feeling like they were being overheard.
This is exactly the kind of situation a full bedroom soundproofing installation is built to fix.
Why Moving to a Detached House Is Not Always the Answer
One of the most common beliefs Jim hears is that noise problems go away if you move to a detached property. In reality, detached homeowners still deal with:
- Road and aircraft noise
- Neighbours with noisy hobbies like DIY workshops or garden rooms
- Dogs barking in adjacent gardens
- Low frequency bass from nearby properties
- Room to room noise transfer within the home
Moving is expensive, disruptive, and often does not solve the problem. Soundproofing your current home the right way is almost always the better option.
The Three Main Causes of Noise in This Bedroom
Before any soundproofing materials go up, the main causes of the noise have to be found and fixed. A main cause means it does not matter how good your soundproofing is elsewhere. If you leave it untreated, noise will still come through.
This bedroom had three main causes, and not all of them were inside the bedroom itself.
Holes in the Structure
When the wallpaper was removed in the alcoves, it pulled the old render away from the brickwork and exposed large holes going directly through to next door. More holes were found when the floor and ceiling were cut open, including one around the bay window bulkhead.
Holes in the structure are the first thing to fix. Until they are bricked up with sand and cement and sealed with acoustic sealant, nothing else you do will give you a meaningful result.
The RSJ in the Bay Window
The rolled steel joist forming the bay window ceiling was another main cause. Steel transmits sound at high speed, meaning the noise level at one end of the RSJ is the same as the other. The RSJ was sound deadened with a visco-elastic membrane, the web was insulated with Rockwool, and all the surrounding wall layers were wrapped around it.
The Hollow Stud Wall Downstairs
This is the one most people would never find. Downstairs, a hollow stud wall had been built to divide the front lounge and dining room. Inside it was another RSJ. That hollow void was acting like an amplifier, picking up the neighbour’s TV from the living room below and channelling it straight up into the bedroom above.
A simple test to check for this yourself: put one finger in your ear and press the other ear against the wall you are suspicious of. If the noise is louder there than on the party wall, that is a main cause that needs treating.
Until that hollow stud wall downstairs was dealt with, no amount of soundproofing to the bedroom itself would have solved the problem.
How Every Noise Path Was Treated
Every step of Quietco’s 4-step soundproofing method was followed on this project.
Party Wall and Chimney Stack
After bricking up the holes, the wall was treated with our TPS80W wall system. All layers were tucked up into the ceiling void and down into the floor void, sealing the system completely so noise cannot bypass the wall through the voids above and below.
The chimney stack was treated with the TPS65W 50mm system. The fireback got its own mini floating frame. More materials go to the chimney stack than most people expect, because the flue connects between floors and is one of the most active noise paths in the building.
Ceiling
The 1930s lath and plaster ceiling was already doing good acoustic work and was kept in place rather than removed. The area cut open to access the ceiling void was patched with 15mm sound board, then the full ceiling was overboarded with another layer of 15mm sound block board. Learn more about ceiling soundproofing here.
Loft
The gable wall in the loft on the shared wall side was insulated with Rockwool. The attic floor was also insulated back from the party wall. This stops noise travelling over the top of the wall system and back down into the bedroom.
Window Wall
The bay window wall was treated with the TPS65W system. As well as the acoustic improvement, this also addressed condensation that had been building up on the solid brick wall, as the system has strong thermal properties when installed correctly.
Hollow Stud Wall Downstairs
The RSJ inside was sound deadened with a visco-elastic membrane and the web insulated with Rockwool. The wall was then overboarded with 15mm sound board. This stopped the hollow void from amplifying noise and removed the channel sending the neighbour’s TV up through the floor into the bedroom.
For a full picture of what a professional installation looks like, Quietco’s solutions pages are a good starting point. You can also book a free noise diagnosis call to talk through what is happening in your own home.
The Results
Watch the full video walkthrough of this project:
Eight weeks after completion, here is what the homeowners said:
- They had not heard anything from next door
- The TV noise that used to keep them awake had completely stopped
- They could have normal conversations without whispering
- They knew it was going to be messy and a lot of work but said it was absolutely worth it
Their exact words were “We used to be able to hear neighbours talking and hear everything really, and we haven’t noticed anything.”
Overall, the result was exactly what a full four-step installation delivers when every noise path is treated, including the ones outside the room itself. It is worth putting that into context that research shows that 25% of UK adults lose an average of six and a half hours of sleep every week due to noisy neighbours, almost the equivalent of a full night’s sleep. For this family, that problem is now gone completely.
If you are ready to take the next step, get in touch with Quietco to find out what the right solution looks like for your home.
FAQ
Does soundproofing a bedroom actually work?
Yes, when done properly. This project is a real example. The homeowners went from hearing clear conversation and TV through the wall to hearing nothing at all eight weeks after completion. The key is treating every noise path, not just the party wall.
Do I need to treat rooms outside the bedroom I am soundproofing?
Sometimes, yes. In this project, one of the three main causes was a hollow stud wall downstairs. If you only treated the bedroom and left that untreated, the result would have been disappointing. A proper consultation helps identify where all the noise is actually coming from.
What is the best soundproofing for a 1930s semi-detached house?
Older properties like 1930s semis often have lath and plaster ceilings, solid brick walls, and RSJ steel beams, all of which behave differently from modern builds. The approach needs to match the construction. A floating frame system on the party wall combined with treating all the flanking paths tends to deliver the best results in properties of this age.
Can I soundproof just the wall and skip everything else?
You can, but you are unlikely to be happy with the result. In this project the party wall was only one of several noise paths. Treating it alone while leaving the holes, the RSJ, and the hollow stud wall would have changed how the noise sounded without meaningfully reducing it.
How do I find the main causes of noise in my bedroom?
Put one finger in your ear and press the other ear against each wall, the floor, and the ceiling in turn. The surfaces where the noise feels loudest are your main causes. Do not forget to check walls in rooms directly adjacent or below the room you are trying to treat.
