Ultimately for type nm romex this is directly referenced in the 2011 nec 334 23 but only points you to comply with 320 23 type ac as does 330 23 type mc.
Romex wiring in attic.
An attic that is accessible which is defined by the nec as having a permanently installed stair or ladder in place must have protection for any cables that run across the top of the attic floor joists or within 7 feet where they run across the face of rafters or studs.
Attics with permanent access stairs ladder.
Plastic boxes and flexible nonmetallic cable commonly called romex put electrical wiring projects within the skill range of every dedicated diyer.
Most of the wiring in a modern home consists of runs of nonmetallic sheathed cable or nm cable also known by the popular brand name romex.
Nm cable is simply a bundle of individual conducting wires wrapped in a plastic vinyl outer sheathing.
Nm cable also commonly known by the common trade name romex is the most common form of electrical wire.
While one person holds the flashlight the other person should use a staple gun to run the wire along the rafters from one entry hole to the other.
The national electrical code nec outlines specifications for securing nm cable and other electrical wiring.
Normally the cables carry 10 12 or 14 gauge conducting wires for individual house circuits.
A pull down attic ladder does not count.
You must protect cables located within 6 of the attic access hole.
Bring all of the wire up into the attic.
We won t cover many other house wiring details.
Nm cable must be supported by framing when running through walls ceilings and floors.
Most local building authorities follow the nec recommendations but in any case the local rules are the ones you must follow and they are the specific.