ouuuu I SO need to do this for an outside ceiling - yep, ceiling.. crud it's 11' up... blah... How to Repair Drywall Tape That Is Separating from Your Walls ... If you have drywall tape separating from your wall, it is best to take down the peeling tape and install new tape. Here is how to do this. You will need drywall tape and spackle (or equivalent paste).
Whether you're finishing a basement, repairing a damaged wall, or hanging drywall in a new house, these taping tips will help you make smooth, invisible seams, even at inside corners. Find simple tricks for fast, flawless drywall finishing at http://www.familyhandyman.com/DIY-Projects/Wall---Ceiling/Drywall-Taping/tips-for-better-drywall-taping
Drywall Installation: Drywall Tape and Top Coat Wall to Ceiling Angle - YouTube
Tips for Better Drywall Taping. Gonna need one of these bad boys.