We came back from 10 days vacation and within 24 hours my basement moisture detector went off. Fortunately I had placed it within 6 inches of the toilet waste line from the 2nd floor. There is a new slow leak that is slowly creating a small puddle. It is clearly coming from the joint about 5 feet above the basement floor of my 1911 Minneapolis home. I was concerned that the toilet was leaking and finding it’s way down the pipe. However above the joint the pipe is completely dry.
What is going on? Any guidance would be appreciated.