Can plumbing just “spring a leak” if there’s been no stress on it? My 30 year old townhouse has copper pipes and I noticed a wet spot in the ceiling in the basement last night. Got the ladder out and peered up into the ceiling from the work room (could see the pipes going around the area of the wet spot from there) and could see a slow drip coming from the elbow joint of one of the pipes. The thing is that it is in a part of the house that would have not outside stresses on it (e.g. Temperature swings, movement, etc.). Before I rip open the ceiling and get out the torch to start sweating one elbow joint (not a problem for my skills) I want to make sure it isn’t something bigger (beyond my skills and more expensive).