Found the Leak!

Our tile contractor came back on Saturday morning and cut a small square in the ceiling to expose more of the piping and there it was.  A big crack in the drain's vent pipe.  It was obvious that the crack was the result of either demolition or construction, but what we couldn't figure out was why we didn't discover this the many times we ran the water in the shower before.  Our tile contractor thinks that it's possible that some water backed up into the drain pipe but froze during one of our cold snaps (we had temps below 0 and wind chills in the -20's in December!).  When I went to take a shower that one time, the hot water melted the ice and allowed the water to flow through the crack.  Maybe?  Who knows.  However, we now have a working shower!!  Bad news is that we have to paint a good portion of the first floor (darn open floor plans).  Not what we had planned for the next couple weekends!  The tile contractor comes back tomorrow to repair the ceiling...the square and the spot where the water initially came through.  We are grateful that it was an easy fix, though!