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 an 11 foot ceiling, we recommend an 18 inch downrod and this will have your blades 8 Â½ feet off the ground. And this 2 foot pole is perfect for a 12 foot ceiling. Likewise on the 13 foot ceiling we recommend a 36 inch downrod, and for a 14 foot ceiling we recommend a 48 inch downrod.n an 8 foot ceiling, we recommend the standard pole which is a 3 Â½, 4 Â½ inch downrod that comes with the fan. This will keep the blades at least 7 feet off the ground. We also recommend the standard downrod on a 9 foot ceiling. However, some manufacturers will include a 6 inch downrod.