We live in a condo and have a problem with noisy (whistling / shrieking / whooshing) pipes in our bedroom wall. We've identified one or two fixtures in the building that are the source of the noise, but they are in other units (not immediately adjacent to our unit) and are in good repair. The association is hesitant to commit to unknown repairs and the plumber we called out was not helpful. The noise is still loud enough to wake us up about once per week.
Does anyone have clear ideas on what's causing this noise? Tips on how to find and fix the problem?
I'm not sure how likely each of these is or how I deal with any of them. Tips would be appreciated. I'd also like to minimize time where the bedroom has open drywall, so ideas about sequence would be helpful too.
- pipe in the wall has a problem/constriction - needs to be replaced
- pipe is resonating - needs to be fastened
- wall is resonating - need to isolate pipe from wall (or make the drywall thinner)
- pipe and wall are ok, just have noisy neighbors - need to soundproof the wall
I've done a fair bit of talking to the neighbors (who are very friendly and helpful) and figured out that the noise happens when the unit one floor below ours and one unit over (we are #402, they are #301) turns on their kitchen sink. The noise is immediate when the water starts to flow and continues until they turn their sink off. This is not water-hammer - it's a whistling/shrieking noise that's constant while the sink is on. The noise happens from both hot and cold taps. We hear basically no noise from #401, even though their sink is just on the other side of our bedroom wall. We do hear some noise when the sink runs in #201, but it's not as loud as #301. No noise from #101. The building is quiet and well-built overall - we almost never hear our neighbors - this noise is the exception.
The noise in our wall seems to coming from a single point centered ~6ft off the floor (it might be two points that are just a few inches apart - one for hot and one for cold). The sink pipes in #301 enter the wall ~5ft below our floor (plus some airgap between floors), so I don't think we aren't hearing their sink directly - but instead the noise from this point in our wall.
The noise was extremely loud for awhile (loud enough to wake us up each time it happened). Then our neighbors in #301 replaced their kitchen faucet (apparently it was somewhat loud for them too). The noise in our wall got less loud (and the highest pitched parts went away). When the noise didn't go away, we had a plumber out and they reduced the flow into the #301 sink by turning down the taps under the sink - that reduced the noise temporarily, but it has returned to the same level a few weeks later. The noise is still loud enough to wake us up about once per week. We're not light sleepers. But unfortunately our neighbors have an odd dishes washing schedule - both early and late hours.
The building is older, but our bedroom wall is drywall. I drilled into the wall and used a borescope to take a look - the pipe in our wall is copper and seems to be running a few inches off the stud and touching the drywall (or very close to it - hard to tell with the fish eye lens). There is no insulation between our bedroom wall and #401. The floor in between the walls does seem closed off.