On Fri, 17 Feb 2017 10:50:25 -0800 (PST), Rednadnerb
wrote:

My neighbour has a pool of water that mysteriously appears on her bathroom floor at random times usually once or twice a week.
It appears on the floor in the 18" space between the toilet and the bath and appears even when she is not in the flat.
I strongly suspect that it is coming over the top of the pan as I have found the lip to be wet (she is in a 1st floor flat so is this even likely?)
It has been going on for ages, I have brilliantly suggested a time lapse camera but she won't have that in her bathroom. I have also suggested putting one of those blue things in the cistern.
Any other ideas as to how to get to the bottom of the mystery pool of water?

A light sprinkling of talc should reveal where the water is coming
from (assuming the floor isn't white).