Romex is a well-known brand name for NM, or non-metallic sheathed, cable, so commonly used throughout residential wiring that the brand name has essentially become the generic term many people use for this cable type regardless of the actual manufacturer.
This cable type, featuring insulated conductors bundled within a flexible plastic sheath, has become the standard choice for most interior residential wiring applications, offering practical, cost-effective installation for the wall and ceiling wiring runs found throughout typical homes.
Because Romex, or NM cable more generally, is designed specifically for interior, dry location use, understanding its appropriate applications versus situations requiring different cable types, like outdoor or wet location applications, matters for both code compliance and long-term wiring reliability.
What Does Romex Involve?
- Insulated conductors within a flexible plastic sheath
- Standard interior residential wiring applications
- A well-known brand name genericized for NM cable broadly
- Appropriate use limited to dry, interior locations
Why Is Romex Important?
As the practical standard for most residential interior wiring, Romex, or NM cable, represents the material most homeowners will encounter throughout their home’s electrical system, making basic familiarity with this cable type genuinely useful for understanding home electrical infrastructure and any related maintenance or renovation considerations. This widespread use has made the term essentially synonymous with residential electrical wiring in everyday conversation.
Because this cable type isn’t rated for outdoor or wet location use, any electrical work in these environments requires different, appropriately rated cable, making this distinction worth understanding when planning outdoor electrical projects or additions. This basic understanding helps homeowners engage more confidently in conversations about their home’s wiring.
Romex vs. NM Cable
These terms describe essentially the same product, with Romex being the well-known brand name that has become generically used, and NM cable being the technical, generic term for non-metallic sheathed cable regardless of specific manufacturer.