Squeaky floors are usually caused by floor joists, sub-floors or finished floors rubbing against each other as you walk over the area. Other causes include loose pipes or heating ducts rubbing against the joists. Squeaks can usually be eliminated by “tightening up” the loose boards, pipes or ducts. Fixing squeaks is best accomplished from a basement or crawlspace under the floor. If you have a finished basement or the squeak is on your second floor, you will need to resort to top-down fixes.