Yes, this is a practical necessity [424.38(A)]. But as with any other conductor, you must take care to prevent mechanical damage.
You cannot route heating cables through or under walls [424.38(B)(4)]
Yes, you can do that. But the purpose must be to control relative humidity and the cables be used only in those portions of the ceiling that are unobstructed to the floor (by shelves or permanent luminaires) [424.38(C)].
- False. The minimum distance is eight inches [424.39].
- That depends. You can alter the cable using only splices identified in the manufacturer's instructions [424.40]. The manufacturer may not permit a splice at all, or may permit it using only specific kinds of connectors.