Leak or condensation

[jrtrrror]

So, just curious. Whilst replacing some worrying pipes within the partition wall at the rear of the shower enclosure, I discovered the following...There is a cold water pipe feeding the next door shower.(The showers are back to back) Part of it is a copper pipe into a compression fitting. Strangely, when the shower is in use to this COLD pipe/joint feels ever so slightly damp. If I run my finger around the nut, my finger glistens as if ever so slightly damp. However, after a short time and the pipe has returned to room temperature, all appears dry and remains fully dry until the shower is used again. Im quietly confident that it is just condensation, and not a slight leak when the shower is run, but is there a way of being sure.
Ta

 

[PETE 123]

High warm humidity in room on cold pipe.

 

[ShaunCorbs]

Yes normal insulation helps

 

[jrtrrror]

Yes normal insulation helps

Umm, I've just been to check on the pipes and found another joint that is a little damp. I can't tell if it's leaking or condensation. I didn't notice it yesterday when I first did the installation. I've wrapped some toilet tissue around it 3 or 4 times to see if it gets damp. Perhaps this will add a little insulation over night. I'll check in the morning and see how wet it is. It's on another fitting, with a compression fitting into plastic. I think King of Pipes mentioned in another thread that he sometimes wraps PTFE tape around the olive when making compression joints onto plastic.