plumbing ( noisy pipes )

[mickcoulson]

hi..... i have just had a leak repaired under my bathroom floor. the O ring in the cold water feed pipe to the bath tap had perished. the plumber who mended the leak got access through the kitchen ceiling ( big hole, water damage ) we are now waiting for the plasterer to patch up and re-skim the ceiling. now for the problem. since the plumber mended the leak ( he used a flexi pipe ) every time we run the hot water tap in the kitchen or run the shower, there is a tapping noise which sounds like a dripping pipe coming from the pipes under the bathroom floor. i have checked for leaks and everything looks dry. any ideas or advice from anyone would be greatly appreciated.
cheers,
mickcoulson

 

[palerider45]

sounds like expansion in the pipework to me, if its all dry and no sign of a leak this is possibly all it is. nothing to worry about if it is. when he repaired the leak he may of altered the pipe position so it may be tight against a joist causing a noise when hot water runs and pipe work expands against joist. Ask plumber to return just to check if your worried

 

[mrgas]

I suspect that during the repair the hot pipe has been moved and is now pinched against a joist or another pipe or floorboard. When a hot tap is run the the pipe expands and makes the juddering, dripping, expansion noise.
Why did the plumber use a flexible pipe? It isnt really a proper repair in my opinion, call me old fashioned if you like.........
doh ....palerider got in first.... whilst i was pondering flexis..

 

[bengasman]

You are old fashioned.
I can see the logic though. Access from underneath, would not like to try and solder it with plenty of wood and possibly combustible dust very near, nor do you want compressionfit under the floor.

 

[mickcoulson]

You are old fashioned.
I can see the logic though. Access from underneath, would not like to try and solder it with plenty of wood and possibly combustible dust very near, nor do you want compressionfit under the floor.

gentlemen............ the pipe the plumber replaced was a cold water pipe. the pipe that is knocking is a hot water pipe. will that make adifference ?

 

[mrgas]

Often hot and cold pipes run close to each other. It is well possible that in the repair of the cold pipe the hot one was moved. Can you see the hot pipe through the hole in ceiling? If so try and move it you may find that the noise stops.

 

[mickcoulson]

Often hot and cold pipes run close to each other. It is well possible that in the repair of the cold pipe the hot one was moved. Can you see the hot pipe through the hole in ceiling? If so try and move it you may find that the noise stops.

i have moved hot water pipe and as far as i can see there is only one place where they touch. i have wrapped some lagging around the pipes to seperate them but am still getting the2 dripping" noise.