When do I use riser-rated cable?

Riser cable is appropriate for any kind of vertical/horizontal cable run between floors that does not travel through plenum spaces. A quick way to check this is by asking "is there air being pushed or pulled through this vicinity by means of any sort of forced ventilation system?" if the answer is "Yes", then you should be using Plenum cable. If the answer is "no", then riser is sufficient. If you are running cable through walls only, and not between floors in a non-plenum space, then CL2 or CL3 cable is all you'll need. Keep in mind, as always, that you can substitute Plenum for Riser, and Riser for CL3, but you can't do it the other way around, as the restrictions increase as you move from CL3 to Riser to Plenum.

For more information about ratings, see our guide to cable ratings.