We just moved into this house in December and within the last 2 weeks or so I noticed that the carpet in front of the bathroom door would be wet but nothing anywhere else. I thought maybe the bathtub overflow drain was somehow getting water in that one location but wasn't sure and didn't worry too much about it until the floor drain in front of the dryer started backing up. When a person takes a bath, the water overflows from the floor drain and if you run the washing machine it overflows from the floor drain and comes up the bathtub as it drains. The day we noticed this problem if you flushed the toilet it would also come up and then slowly drain back down but that only happened that day while everything else is continuing to happen. We tried to snake the floor drain with a 25ft snake but it did nothing.