Since the house needed to have two of the rooms’ floors redone, I am starting to wish I was Tim Allen or if he’s right by my side. Stage 1 (Removing stuff from room) :

Stage 2 (Ripping out previous aging floorboard, part of the reason is thanks to that leaking, old water heater) :

Edit: If you’re curious as to why there’s a backerboard down on the floor there, well, there’s a gaping hole as discovered.