I'm finishing a 13x13' room in a friend's basement. I finished my own basement including the electrical that involved installing a six-circuit sub-panel with a 60-Amp feed from the main panel located in the garage. All was Code compliant, so I am reasonably fluent in household electrical wiring.

With my friend's basement, I plan to use grooved 1" or 1.5" rigid foam board. I will secure the foam board on to the poured concrete slab walls with 1x3" furring strips via a powder actuated gun and drive pins. Standard one-half inch drywall will follow.

Does Code allow slitting the rigid foam board insulation and pressing sheathed electrical cable into the slitted cavities? Or, does Code require running conduit down along the furring strips (outside the drywall) to an electrical outlet? If the former is allowable, what kind of outlet boxes would you recommend along with how to fasten them given the situation described?

Thanks.

This is similar to wiring an insulated concrete form (ICF) house.

Common practice is to cut a slot for the wire and then use a few dabs of foam to hold it in place.

These reference that I am linking to show a special box, but on also shows using a regular Carlon box (blue). But note the tab on side. That tab will be screwed or nailed to the front of the furing strip.

NM does not need to be protected if it is more than 1 1/4" from a nailing surface (furing strip). Run it several inches from the furring strips and then over to the box.

Also note that these boxes have to be shallow. So, at least in some places, they used a 4 sq box and then put a single gang mud plate on it. That gives you much more space for box fill.

http://www.amvic-pacific.com/Downloads/Tech%20bulletin%20-%20Electrical%20Installation.pdf
http://www.icfelectrical.com/icf_electrical_box.asp