My house was built on a crawl space in '95. Over the last 10 years, some interior doors have slowly become misaligned. Convinced the floor was settling, I finally crawled under the house, with a bunyip level(tube mostly filled with water ), and took careful measurements at all 10 piles. To my surprise, they are all almost dead level! I then checked the floor joist in the area where the problem is worse , and, it too is fine!
This house does have a large, unfinished upstairs, we have used as an attic. Is it possible the the ceiling is actually sagging and NOT the floor?
Any suggestions on how to tell? What can be done to correct it? One of the bedroom doors is significantly bowed.