Condensation vs leak

snipped-for-privacy@mdfs.net explained on 15/08/2017 :

Leave the pipe unused for several hours, so as to allow it to achieve the same temperature as it surroundings, maybe wipe away any moisture in the meantime. If after that there is still moisture on the pipe, it is due to a leak rather than condensation.

You can deter condensation to some extent, by insulating pipes.

Tape clear plastic/plastic film to the wall. Leave for a while.

Moisture on it: condensation, under it: leak (or residual moisture in the wall from condensation).

Thomas Prufer

eh, just re-read the post.

Adjust what I said for where the pipe is, and where the cold is coming from...

Thomas Prufer

I pulled all the insulation off, dried all the pipework, then tied lengths of tissue paper at strategic positions. By the position of the one soggy length of paper it's confirmed it's a teeny tiny leak from a capillary == join. Probably easiest to chop out a decent length of pipe to the next == join. Bugger that it's the rising main, it means shutting the whole house off.

I would just remove the old joint, clean the pipe ends with emery cloth and maybe a maybe a file so that they are shining put flux on the pipe and resolder using a new joint.

The pipes must be clear of water to unsolder and then resolder.