Water Hammer (??) Noise Caused by Faulty Water Pipe System

[kcoh193]

[FONT=&amp]Hi Good Day! I am new here and would like to seek good advice in this forum, for disturbance noises caused by faulty water pipe system. [/FONT][FONT=&amp]

I live in a 5th floor unit of Singapore public housing, in recent months it has been a loud “knocking” noise intermittently coming from the upper floor and it’s a serious disturbance noise even it happening in the middle of night, my family has been trying to endure but the problem does not seem to go away.

I had spoken to an upper floor neighbour and he is aware the noise existence, he advised me to provide a feedback to water department for a remedy action, I've follow a called to water department and a team arrived on-site for assistance, however they can’t carried out further checks for the problem as there were no one at home in upper floor neighbour’s unit they advised me to contact local town council for help, as they explained that the problem could be possible the water piping systems structure problem.

I've follow up contacted local town council and their team did a round of checking, interviewed the upper floor neighbour unit owner but claimed that the family member are not aware of such disturbance noises, hence the team needs to further investigate the problem to determine the root cause.

I’ve noticed that the pipe knocking noises were more intensive frequent in the night from around 8.30 pm onward and I‘ve searched google website and found some information which describes as follow:

{…Knocking noise or sound in water pipes can be due to several reasons, but if there is a ‘knocking’ sound from the water piping, this is known as Water Hammer.This can be heard when the tap turn off quickly and it could be caused by either faulty jumpers in stopcocks at the meter position or pipes which are not securely fastened.

As the moving water in the pipe is suddenly stopped, a shock wave is created through the water which causes inadequately fastened pipes to vibrate and ‘shudder’, thus creating the knocking sound......}

I would like to seek some good advices from this forum here about this noise, whether could be the suspect possible root cause by faulty jumpers in stopcocks (main stop valve?) or water piping system structure not securely fastened cause a random “1 or 2 echo loud knocking noise” intermittently ?

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[FONT=&amp]I hope this would be helpful for anyone good advices here and I would be grateful this issue can be resolved soon.[/FONT]
[FONT=&amp]Thank you and best regards.[/FONT]

 

[rpm]

Welcome to the forum kcoh and I reckon you`ve pretty much covered it with your own reseach.

 

[kris]

Hi there kcoh and welcome to the forum .. Yeh you have kinda answered your question it's simply a case of finding the cause. It could be an isolation valve and the jumper is knocking or it could be a faulty mixer shower ,, in my experience the location of the problem is usually not where the knocking is heard ...It may be more difficult to determine the cause because it's blocks with a shared supply....

 

[kcoh193]

Hi Kris,

Many thanks for your reply.

Please allow me to seek your advices again as I do not have much technical knowledge of plumbing, there are some local constraint here with regards to the public building maintenance works:
1. The water pipes system structure is maintain by local town council team where the water department only take care the water supply and meter portion, residents must take responsibilities of each own house unit interior valve and faucet repair works.
2. In this case, the knocking sounds were heard coming from upper floor of building whereby some neighbours claimed that they are not aware of such disturbance noises.
3. The trouble-shooting process is slow in progress due to difficult of isolation and to determine the faulty component in a common shared water supply system.

I had managed to capture and recorded a short audio file of the “knocking sound noise” but unable to share as the attachment here, also I’ve tried to upload it to Zippyshare.com URL to share here was unsuccessful, kindly is there any way to share the recorded audio file? (For example, share it in a facebook page?)

I would be appreciate for your kind advice and would be very grateful this issue can be resolved soon.

Thank you and best regards.

 

[kcoh193]

Hi All,

I had called water department to seek advices again and shared the recorded audio file with the maintenance team, they have came twice in past 2 days to check and investigate, a senior technical officer went round to each upper floor house units to verify the faucets and toilet flashes for possible cause and he had also checked all the main stopcocks outside the house and found some were not fully opened, he told me that could be the main cause of the pipe knocking noise heard, whereby the jumper washers would be noise source and he has helped to put all of these stopcocks to fully open position. He has advised me to continue monitoring and asked me to give him a phone call next week to update the status.

Kindly permit me to seek advices here that Stopcock should it always be fully open when switched on, as I have always think had it open just enough to get decent pressure and have never put it anywhere near fully open to prevent leaking or dripping happen? Or having the Stopcock fully open will it harm if in long run eventually the spindle jam with limescale and unable to turn it off ? Indeed this is useful information as I could have been totally wrong with my own misconception all the while?

I hope this would be the root cause of the issue and problem
can be resolved soon.

Thank you and best regards.

 

[rpm]

My own view is fully open then turn back half a turn which gives you a little bit of left-right-left movement of the shaft if the valve goes tight, others may disagree though.

 

[ShaunCorbs]

My own view is fully open then turn back half a turn which gives you a little bit of left-right-left movement of the shaft if the valve goes tight, others may disagree though.

+1 and same goes with gate valves stops the shafts sticking too bad

 

[kcoh193]

Hi All,

Thanks for your reply and information.

I had clearer understanding now of main stopcock should be opearted fully open and the jumper washer is a floppy rubber seal with a relatively small free play space won't generate loud knocking sound, nevertheless the water hammer noises heard were from pipes structure which its could be a "lossen component" somewhere that created a vibrate or shudder triggered by the water "shocked wave" flow movement?

Apparently the building water services pipe structure were cemented through base floors and probably won't cause a section of unsecured lossen pipe to vibrate and knocking against the wall?

As suggeated by water department maintenance team, I would monitoring for next few days and update the status accordingly, meanwhile any good advices and suggestions would be definitely helpful!

I sincerely hope this problem can be resolved soon.

Thanks again and best regards.

 

[Sparkgap]

Had a similar knocking noise at home. Cause was (1) washing machine internal solenoid shuts quickly causing a hammer and (2) two pipes in airing cupboard which were slightly touching which the hammer caused to knock together.
You can get water hammer suppressors on the market but simple solution is to have a tee in the water pipe with a short vertical stub (about 100-150mm) of pipe with a capped end sticking up. The pipe holds a bit of air which acts as a cushion and reduces the hammer.
You can also get knocking from bouncing ball valves in water tanks: a slug of water comes through the ballvalve and causes a wave in the tank, ballvalve bounces closed causing water hammer, wave passes and valve opens slightly, another slug of water comes through..... repeat. To the OP is there a water storage tank at the top of the building as it could be this which is the problem?

 

[kcoh193]

Hi All,
Update on the water pipes knocking noises status. Apparently ww are on track to find the root cause, since last Thursday after Water Department maintenance team had turned the upper floor units main stopcocks to fully open position, the knocking noises has seems to "stop" for few days over last weekend.

On Monday the town council team has called to inform the decision is to replace new stopcock valves for 6th floor two house units and scheduled on Wednesday, this is to eliminate the two suspects faulty stopcocks, indeed it is a positive step to solve the problem.

In here typical public housing building has ten floors with approx. 70+ house units sharing a common water tank storage at rooftop, steel pipes structure supplying water services to each floor house unit with a main stopcock valve and a water meter installed at common corridor just outside main door entrance, hence it is pretty easy for anyone to hear any unusual knocking noises, as such it is really a puzzle when upper floor neighbors claimed that never heard knocking noises while the teams carried out investigation?

Now I am hopeful the root cause of this many months long outstanding noises disturbance problem to be solved soon.
Thanks everyone here for supports and your valuable advices. I would say that I have learn many plumbing knowledge from this forum!

Best regards.