Now I understand why joists are important enough to get into a feud with a landlord over! My neighbor did just that, but I did not get the significance of it until reading this article.
He told us that he was moving because a joist in the floor was broken, and the landlord had refused to fix it. I now know that a joist span includes the distance from one wall to the next, so I can see that a joist is not just one little broken board.
In addition to not repairing the joist, the landlord also went up on the guy’s rent. He got out of there quickly. The floor was about to collapse beneath him!