Romex vs BX cable — which should I use?

For most residential applications in New Brunswick, Romex (NMD90) cable is the standard choice, while BX (armored cable) is required in specific situations where physical protection is needed.

The choice between these cables depends on your installation location and New Brunswick's adoption of the Canadian Electrical Code. Romex cable (technically called NMD90 in Canada) consists of insulated conductors wrapped in a plastic sheath. It's less expensive, easier to install, and perfectly suitable for most indoor residential wiring - running through walls, attics, and finished basements where it's protected from physical damage.

BX cable (armored cable or AC90) has a flexible metal armor covering that provides superior physical protection. Under TSANB requirements, you'll need BX in exposed locations like unfinished basements, garages, workshops, or anywhere the cable could be subject to physical damage. The metal armor also provides better protection against rodents - a real consideration in rural New Brunswick properties.

Cost and installation differences are significant. Romex typically costs 30-40% less than BX and installs much faster since you don't need to cut the metal armor or install protective bushings. However, BX provides electromagnetic shielding and is often preferred for sensitive electronics or areas with high electrical interference.

TSANB code requirements in New Brunswick mandate armored cable in specific locations: exposed runs in unfinished areas, commercial applications, and anywhere subject to physical damage. For standard residential wiring inside walls and finished spaces, Romex meets all code requirements and is the economical choice.

Installation considerations matter too. BX requires special cutting tools and anti-short bushings to protect conductors from the sharp metal edges. Romex simply strips away with a utility knife. However, only licensed electricians should be installing either type - most wiring work requires TSANB permits and professional installation.

For your specific project, the location determines the choice. Kitchen and bathroom circuits inside walls? Romex is fine. Running cable along basement ceiling joists or in a detached garage? BX is likely required. Your electrician will know the specific TSANB requirements for your installation location.

Need help finding a licensed electrician to properly install either cable type? New Brunswick Electrical can match you with local professionals who understand TSANB requirements and will pull the proper permits for your project.