Can copper pipe leaks develop even where there's been no stress on the plumbing? My 30-year-old townhouse has copper pipes and I noticed a wet spot in the basement ceiling. I got the ladder out and peered up into the ceiling from the work room (I could see the pipes going around the area of the wet spot from there), and spotted a slow drip coming from the elbow joint of one of the pipes. The thing is, this is in a part of the house that would have not outside stresses on it, like temperature swings, movement, etc. Before I rip open the ceiling and get out the torch to start sweating one elbow joint, which is not a problem for my skills, I want to make sure it isn't something bigger that's beyond my skills and more expensive.