NM cable

[nizak]

Can NM cable be stapled to the underside of floor joists that are above a residential drop ceiling?

Both along the joist and perpendicular to the joists.

 

[Strathead]

In my opinion yes, a drop ceiling is a finish, making 334.12(B) not applicable.

 

[augie47]

Locally the simple presence of a suspended ceiling does not qualify as a "finished basement" and 334.15(C) is enforced.