Dripping from behind shower bar

[Joe1977]

Hi, as per title I've recently discovered a dripping noise from behind my shower bar in the boxed in section. I've attached some pics to help. From what I can see the feeds to the shower are flexible pipes taken off the bath tap feeds. It only drips when the shower is on and then gradually stops when you turn the shower off. It's mains pressure fed from the combi boiler. Obviously I'd rather try and fix it myself if possible. I was going to remove the shower bar and see if there is anything obvious amiss. I guess the only likely cause is the joint from the flexible pipes behind but wasn't sure if this is accessible. I could potentially also cut away the plasterboard underneath the bath to see how wet it is at floor level. My main concern is that it's something that isn't accessible without cutting part of the wall away. Any advice or suggestions would be much appreciated.

 

[terryplumb]

Is there any water showing up anywhere ? The sound you are hearing may be pipes expanding / contracting with hot water running ,and rubbing against something.
Of course if water is escaping it's a leak.

 

[Joe1977]

Is there any water showing up anywhere ? The sound you are hearing may be pipes expanding / contracting with hot water running ,and rubbing against something.
Of course if water is escaping it's a leak.

Yeah I did consider that but don't think it's the case. Hard to say as recently the bath seal was leaking which led to a damp patch on the ceiling below (now dried out). The skirting board in the adjacent room is showing signs of water damage but not sure which issue that's down to. As it's all concealed I don't want to leave it and find serious damage later down the line. I guess the fact there's no more damp ceiling suggests there's no major leakage currently.

 

[terryplumb]

The water supply pipes in the wall behind the shower bar mixer ,are permanently pressurised. If they leak it would be continuous and non stop. They won't just leak when the shower valve is in use ,and stop when it's turned off. It has to be something else. Maybe dripping is water escaping from inside the bath/ showering area ,failed seal ( silicone ) around bath rim maybe.

 

[dal5band]

Push a long strip of carboard or newspaper in there for a couple of days to see if it gets damp.

 

[Joe1977]

The water supply pipes in the wall behind the shower bar mixer ,are permanently pressurised. If they leak it would be continuous and non stop. They won't just leak when the shower valve is in use ,and stop when it's turned off. It has to be something else. Maybe dripping is water escaping from inside the bath/ showering area ,failed seal ( silicone ) around bath rim maybe.

That was the conclusion I came to, it's not the bath seal. Only other thing I wondered was if the shower bar was leaking internally and the water was finding its way back through the wall somehow.

 

[Joe1977]

Push a long strip of carboard or newspaper in there for a couple of days to see if it gets damp.

Yeh think I'll have to cut an inspection hole under the bath and see what's going on in the void.

 

[terryplumb]

You could isolate water supplies to it ,and remove the bar from the wall.
Remove the chrome covers and See if any signs of water ingress behind tiles.

 

[Joe1977]

You could isolate water supplies to it ,and remove the bar from the wall.
Remove the chrome covers and See if any signs of water ingress behind tiles.

I took it off and no sign of water leaking back.
I tried running the shower with the plug in the bath and no noise. Took the plug out and as the water drained it started so I guess it can only either be the sound of the waste pipes expanding or leaking. There isn't enough height for any drips from the waste pipe to make that much noise which just leaves pipe expansion/contraction as the only logical cause. I know it's a relatively new thing though so I'm still not convinced and it's a very regular sound rather than random. Only thing I can do now is cut an inspection hole beneath the bath and see if it's damp.

 

[terryplumb]

Can't see much of your waste pipework in the pic you posted ,just heads into the plasterboard. Is there clearance around it at that point ?
Doesn't seem to be a leak on your supply pipework though.

 

[Joe1977]

Can't see much of your waste pipework in the pic you posted ,just heads into the plasterboard. Is there clearance around it at that point ?
Doesn't seem to be a leak on your supply pipework though.

Yes there is clearance. That's the end wall that the shower is fixed to above. I assume the bath waste T's into the sink waste pipe which would come from the right and then join the main waste pipe to the left which would run vertically. If I go into my bedroom which is the other side of the bath the sound can be heard clearly from the corner, so definitely within that boxed in void.

 

[dal5band]

Try running the shower cold and listen. Then try with hot water. If you get the sound with hot only then its plastic expansion sound - like gutters whenthe sun comes out.

 

[Joe1977]

I've exhausted most possibilities and everything points towards it being the waste pipe expanding from the hot water. It's definitely never been so noticeable or sounded so much like a dripping noise though so have laid newspaper where I can get to and will just have to keep an eye on it. Thanks for all the suggestions, much appreciated.