I'm in the process of removing an old bathtub/shower and replacing it with a walk-in shower. The problem is that a 1 1/2" drain pipe that was once covered by the tub is now eating into where my new shower floor/walls will be. I'd like to redirect it through the bottom plate of the wall, but the wall is flush with a floor joist that's already been notched and strapped. For some reason there's also already an unoccupied notch in the bottom plate.
Here are some pictures:
What are my options?