A herniated disk, sometimes (incorrectly) called a slipped disk, is a common cause of severe back pain and sciatica. A disk in the lumbar area becomes herniated when it ruptures or thins out, and degenerates to the point that the gel within the disk (the nucleus pulposus) pushes outward.
The ceiling fan's downrod must be long enough for the fan's blades to clear the ceiling. A fan with a 12-inch downrod works for a vaulted ceiling with a one-quarter-to one-third-inch pitch. An 18-inch downrod is sufficient for a pitch that is five-twelfths to one-half inch.
For example, if your ceiling is 10 feet in height and your ceiling fan is 12 inches in height, you will need a 1-foot downrod to mount the ceiling fan 8 feet above the floor.he wrong height can also result in an ill-fitted looking ceiling fan. A method commonly used to find the right downrod length is the ceiling height minus the height of the ceiling fan, minus the desired hanging height (usually 8 feet).