I went through 4 pages looking to see if there was an answer first, but didn't see what I was looking for.

Bought our 30+ yr old ranch style home in May 05, and some of the ceilings showed tape separating from the joints. We left most of them as is, except for one room that was really bad, and the drywall was sagging some at the joints. Found out later that the drywall was not installed correctly. Meaning they weren't running with the joists, but opposite them, so on the ends and some of the sides of the drywall was not matching up with the joists. Haven't felt like tearing it all down and putting up new drywall the correct way yet, due to $$$. But, will do it some day. My question, after all that is, how long should drywall tape adhere(sp) on the ceilings, at the joints? There's been no water damage to any of the ceilings, that I can find. I'm just thinking that the original job wasn't done properly, and it's finally showing up.

Any other ideas, and solutions would be greatly appreciated.