I found this little defect in a new construction attic yesterday. This refrigerant line was sweating almost as much as I was–however, I wasn’t creating a water stain on the ceiling below (at least not yet anyway)… So easy to miss this type of thing when you can’t wait to get outta there!
Good eye, Arthur.
Very often the water flows inside the insulation to some place else…
It is often too hot to make it to the ceiling, but it will make it there eventually (as the weather changes).