Extremely noisy pipes

[richie4236]

Recently bought a house and having a few plumbing issues. Water pressure is good and nothing appears to be leaking, but the pipework leading from the bathroom to the tank in the loft has a strange quirk. Sometimes, when you flush the toilet or run water in the sink, the pipework under the floor makes a very loud high-frequency hum. You can literally feel the vibration coming through the floor tiles, and as you walk out of the room the sound seems to be coming from the route the pipes take to the tank (bathroom, landing, airing cupboard and into the loft space).

The noise goes on until the cistern is filled (which takes a longer than it should). It's annoying, but also, my worry is that it will cause joints to fail over time. It doesn't happen every time. Maybe once in every ten flushes of the toilet.

A previous owner of the house was a very keen, but very inept, DIY enthusiast. Corners have been cut everywhere and his work is very extremely sloppy and haphazard (cupboards and shelves glued to walls, silicone sealant used instead of Polyfiller, etc). He had seemingly tried to fix the vibration by driving steel screws into the water outlet in the cistern - presumably with the intention of slowing the flow or water by partially blocking the pipe. It was when I found these and removed them that the vibration started. I'm not sure if the vibration is caused by something he's done, or not done, to the pipework.

Is there there a particular reason pipework vibrates? Any straightforward fix I can apply? Had considered cutting a length of flexible pipework in near the tank to deaden the vibration, but don't know if that's the way to go. Any thoughts gratefully received.

 

[Burnerman]

A bizarre 'cure' if there ever was one.....
I'd fit a new fill valve in your loft tank, just for a kick off.
John

 

[cjard]

If the toilet refill is taking longer, examine the fill mechanism. I have that problem on a ballcock in my flat bathroom, it's made by usamp, or siamp or something like that, and a diaphragm has split causing water to come out of a tiny pinhole at the end of the tap block instead of the proper outlet.. Apparently a common problem, I just haven't got around to fixing it

The hammering has a reasonably simple cause, some appliance on the pipe network is consuming water at just the right flow rate to make the initial rush of water and resulting back pressure wave start a resonance in the pipes. Fixes would be to change the way the flow starts and stops or alter the resonant characteristics of e pipes by re routing them or fixi them different,y so the resonance cannot start up/bangs fade to nothing rather than perpetuating or amplifying..

 

[richie4236]

If the toilet refill is taking longer, examine the fill mechanism. I have that problem on a ballcock in my flat bathroom, it's made by usamp, or siamp or something like that, and a diaphragm has split causing water to come out of a tiny pinhole at the end of the tap block instead of the proper outlet.. Apparently a common problem, I just haven't got around to fixing it

The hammering has a reasonably simple cause, some appliance on the pipe network is consuming water at just the right flow rate to make the initial rush of water and resulting back pressure wave start a resonance in the pipes. Fixes would be to change the way the flow starts and stops or alter the resonant characteristics of e pipes by re routing them or fixi them different,y so the resonance cannot start up/bangs fade to nothing rather than perpetuating or amplifying..

Great answer. Many thanks. I'll change out the cistern and take a look at what's up in the loft space to see if I can modify that in a simple way.

The toilet does have an isolator valve. Would closing this partially work as a temporary fix?

 

[Burnerman]

Just to confound the situation, isolator valves that aren't fully open can cause noise in the pipes - or they do on high pressure systems. Nothing to stop you giving it a go though!
John