Sequence for pulling Romex through vertical foam chases before hanging drywall

Pulling Romex through vertical foam insulation chases requires mapping box locations, feeding 12-gauge or 14-gauge NM-B wire from the top plate using fish tape, securing junction boxes, and verifying code-compliant setbacks before hanging drywall.

Traditional masonry framing requires extensive stud drilling, consuming up to 30% more rough-in labor compared to pre-molded foam raceways. In continuous insulation assemblies across North America, routing electrical runs through factory-formed vertical channels preserves thermal boundaries while aligning with National Electrical Code (NEC) standards.

If you only do one thing: Pull NM-B cable through the vertical foam chases prior to securing electrical boxes to maintain clear clearance for feeding conductors through rear box knockouts.

1. Map and cut box locations: Mark outlet heights 12 to 18 inches above the subfloor, then cut foam openings adjacent to integrated studs using a utility knife to fit standard single-gang plastic boxes.
2. Drop cable from the top plate: Feed 14/2 or 12/2 NM-B (non-metallic sheathed cable) down through the pre-formed vertical chase using a standard 25-foot or 50-foot fiberglass fish tape.
3. Feed wiring into junction boxes: Guide conductors through the box knockouts, stripping outer jacketing to leave at least 6 inches of free conductor inside the box per NEC Article 300.14.
4. Fasten boxes to embedded studs: Seat each box flush in the mortised foam cavity and anchor it directly to integrated panel studs using two 1-5/8-inch coarse-thread drywall screws.
5. Air-seal raceway penetrations: Inject low-expansion polyurethane foam around the perimeter of each electrical box to seal air leakage pathways and lock the enclosure firmly in place.

• Watch out for: Shallow cable placement resting less than 1-1/4 inches from the panel face; if cables sit closer, install 1/16-inch-thick steel nail plates over the chase to guard against puncture from 1-5/8-inch drywall fasteners.
• Watch out for: High-expansion spray foam, which generates excess pressure capable of displacing electrical boxes out of alignment with the 1/2-inch or 5/8-inch drywall plane.
• Watch out for: Exceeding conduit-fill thermal limits by pulling more than two multi-conductor cables through a single 1-inch to 1-1/2-inch vertical chase.

Consult a licensed electrician and local building inspection departments to confirm local code requirements and inspect rough-in wiring before closing the wall assembly.

General information only, not medical advice. Decisions about health, treatment or wellbeing should be made with a doctor or other qualified healthcare professional.