I have a wall between the bathroom and bedroom.

The sound transfer between the bathroom -> bedroom is huge. Mainly the water sounds from the toilet and shower.

I'm about to tile the whole bathroom, floor to ceiling, so I want to know how I can improve the sound proofing between the two rooms.

The wall is a single layer of brick.


  • 1
    Are the sounds you're hearing from the water fixtures (toilet flushing, shower spray), or from the pipes / drains in the wall?
    – mmathis
    Commented Oct 6, 2017 at 21:21

2 Answers 2


Sound is actually vibrating air molecules. This is not the same as moving air - hence why sound can come through walls, although it is hindered as it does.

I suspect (assume?) that the sound that is bleeding between bathroom and bedroom is low frequency sound. A brick wall is going to be excellent at stopping the sound, unless it's not isolated from the vibration of the water through the pipes.

Which leads me to my second assumption: are your pipes mounted to the brick? If so, that's going to be a big source of the problem. The vibration of water in the pipes will vibrate the brick, which will vibrate the air in your room. It will sound like a low frequency rushing sound.

Additional sources of sound will be the water on the bottom of the tub, which will vibrate the floor. Low frequencies love to go around objects and make things rumble.

All that being said, if your rooms share a door then that's probably most of the problem. Typical interior doors don't stop much sound.


  1. If your problem is pipes mounted on the brick, you will need to remount them using some sort of isolation bracket (search for neoprene isolation bracket).
  2. If you are drywalling over the brick, build a soundproof wall (isolate it from the brick).
  3. If the sound is coming through the door primarily, this is much harder to fix. Interior doors are supposed to allow airflow, which is the enemy of soundproofing. You could weather-proof it and install a heavier door (heavier means better at soundproofing) if you liked, but it will be hard to get good isolation here.
  • "Interior doors are supposed to allow airflow".. Why? Is there danger in sealing an interior door with a door seal kit/foam? (There are still vents.) In my case, for a bedroom. Too much sound going between bedrooms in the house. Commented Apr 5, 2019 at 5:56
  • @SilentSteel You can feel free to do your own research, but there are two reasons I said that: 1) if the air cannot come in and out of the room regularly, the air will get stale and that can be unhealthy (dust accumulation, etc.). 2) HVAC systems need a certain amount of airflow in and out of a room. Now, that being said, if you have an air return and a register in the room, then I would assume that the airflow would be perfectly adequate, and an under-door gap is not necessary at all.
    – wildbagel
    Commented Apr 10, 2019 at 16:38

I would look at a rockwool insulation product, such as Roxul Safe 'n Sound. I used this in my basement ceiling and all interior walls in the basement, and it's made a HUGE difference. You should also make sure the door between the rooms is solid core (the chains sell doors specifically marketed for sound reduction) and that it closes tightly. Just a tiny air gap lets through a huge amount of sound.

  • The wall is a single layer of brick. I've updated the question saying so.
    – CathalMF
    Commented Oct 6, 2017 at 20:01
  • Well that rules out rockwool. I'd focus on the doorway in that case.
    – Drew
    Commented Oct 6, 2017 at 20:03
  • The doors are solid and insulate a lot of sound.
    – CathalMF
    Commented Oct 6, 2017 at 21:38
  • I'm considering this for a non-brick wall. I prefer not to use rock wool based products. (Long story but rock wool very similar to asbestos in my tin hat wearing opinion.) Any alternatives you'd recommend? Commented Apr 5, 2019 at 5:58

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