How should I repair old drywall tape seams showing at wall and ceiling?

Question

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.

Thanks!

Answer 1

Is it normal for a contractor to use very little mud on a tape joint? Yes the thinner the coat the faster it dries. When recoating I would use topping mud over or instead of hot mud, you won't need much to hide the lines and topping mud is much easier to sand. Since your tape is well attached I would clean the area and skim coat it and sand. I don't use corner tools, usually a wide knife to taper the skim coat.

If you have high humidity in the room this may have caused the problem and a thin skim coat should last longer than the original because of the additional mud.