ALL the pipes in the loft are lagged with the standard polythene sleeves. There is one vent pipe into the cold water tank which is dripping with condensation inside the sleeve. The pipe rises from floor level to the height of the tank , about 12 feet since the tank is right in the apex of the roof. Removing the sleeve shows a fair amount of copper corrosion, and it's wet. I removed the sleeve at the bottom of the pipe hoping it would air dry there, I think I really need to remove the sleeving all the way up. It's so bad I have a drip tray underneath which I have to regularly empty, and I can't see that the vent is ever used, so no water in it. I'm supposing it is a vent from the hot water tank, but that is on the floor below and a good 30 foot run of pipe up, then along the floor till coming round to the tank.
Suggestions ?
Suggestions ?