We recently purchased a home that is about 20 years old and I have noticed that the downstairs hardwood flooring is not level in several rooms. The house sits on a crawl space and has a sump pump. In the living room there is a floor joist that bows upward in one place and in our bedroom there is a place where it slopes downward toward an interior wall. Also, in the breakfast nook and dining room which runs long the back of the house the last foot or so of flooring slopes downward about 1/4 of an inch. We had the home inspected by a reputable home inspector and he didn't seem to think it was an issue. I really didn't notice it as much at first but the more time I spend here the more it bothers me. My question is why does the floor bow upward in one place downward in other random places? Also and most importantly,what can I do about it? Should I be worried? Thanks in advance-LJ