Terry Coombs wrote:

Gary , the scenario you presented is physically impossible ! Water
condenses on COLD surfaces , not warm . I suggest the cold attic chilled
the duct causing the warm moist air inside to condense on the INSIDE .
It's still gonna cause the damage you described as the condensation
wicks out into the surrounding drywall/plaster/whatever . Solution is
the same ...

I stand corrected. You're right. And as you said, still the same
back to bathroom ceiling problem and the insulation did fix the
problem.