Addition is 18 years old and seams are appearing in ceilings. Had no issue replacing tape in ceiling test butt joint but, on closer inspection, I see lines in the ceiling tape where the walls meet.
I tested a spot and see that the tape is strongly attached, but there is actually almost no mud covering the tape on the ceiling. Very faint lines are visible (I live in Chicago with significant climate swings so some settling and movement is to be expected).
Can / should I simply mud over the seams with a corner tool and 20-minute hot mud? Is it common for subcontractors to use so little mud on ceiling corners like this?
I hate to redo all joints if the tape isn't failing and this is simply cosmetic.