Its very satisfying when you walk into a home, look at the water damage, document the affected area with an infrared camera, and conclude that there is a plumbing leak in the wall, only to find out later that you were right-on! I originlly suspected a roof leak, but since the arera of concern was on the lower level, and the upper level had no damage, the water had to be coming from the lower level. We opened a small section of drywall to check it out and guess what.... I was dead-on! There was a plumbing leak that was spraying water on the inside of the wall cavity.