Forgot to mention this is in a basement. I saw some places that said it was okay to place the drywall against the ductwork but I can't help but think that you need room for expansion and contraction. I'm not sure if condensation will occur in the summer since the basement tends to be cooler than the rest of the house.
I had a drywall guy here the other day and he mentioned that about half of his work was repairing drywall that was placed against ductwork that eventually crumbled.
I had a drywall guy here the other day and he mentioned that about half of his work was repairing drywall that was placed against ductwork that eventually crumbled.