Securing NM wire runs in the attic across joists - bundle or not?


I’ve spent the last few hours looking through existing forums to get an answer to this question, and if I missed it apologies for recreating a thread and wasting everyone’s time.

I am looking to run several NM (12-2 and 14-2) wires in my attic the entire length of the house. I am trying to do everything to code both for safety and for inspection. I so far have learned (from a previous thread) that I must “support AND secure” the wires every 4 and 1/2 feet but I do not see anything regarding what means of securing these wires is acceptable.

Since there will be several wires I want to find the most efficient approach while still being safe. What I would ideally like to do is use these mounting wire ties ( which have an eyelet on the end. So the base question is, is this an acceptable method as apposed to using wire staples?

My next concern which I caught onto from yet another previous forum was the heat generation issues when bundling wires together. Currently none of the runs in my attic are secured until they break out and go parallel to the joists (I have an 1970’s home). I would hate to inadvertently make a fire hazard while trying to ironically make my installation more secure than the existing. What is the maximum number of 12-2 and 14-2 wires that can safely be bundled together, and can/should I mix them.

Any help is greatly appreciated.


It would be better to use 3M Stak-its.

Just in case you don’t understand what Jim said.

Running wires from one end of the house to the other - how far is it? If wires are greater than 50 feet you may want to up size them to control voltage drop.
Check out this article.

Chuck Boldin

Staple every 4 foot.

Kind of sounds like a Modular or Kit home with the bundling of the NM… is it?

Any NM cables bundled together for more than 24" will require an ampacity adjustment. Also if they’re run in an attic space above the insulation then they would also be adjusted for the attic ambient temperature.

Also they can not be within 6’ of access or must be protected, which is usually done by running a 2x4 parallel to wires. some guys staple and protect anyways. But definitely if within 6’ of access.

Just use electrical staples every other truss. 2 cables under a staple max. Don’t make this harder than it is.