What type of insulation is most commonly used in residential wiring?

The most commonly used insulation in residential wiring is non-metallic sheathed cable, often referred to as Romex. This type of insulation is favored for several reasons. Firstly, it is lightweight and flexible, making it easier to handle and install in various residential applications. The non-metallic sheath provides protection for the insulated conductors inside, shielding them from physical damage and minimizing the risk of electrical shorts or other hazards.

Additionally, non-metallic sheathed cable is designed to meet the National Electrical Code (NEC), ensuring it fulfills safety standards required for residential wiring. Its design includes multiple insulated wires bundled together, which allows for efficient and safe distribution of electricity throughout a home.

Other types of insulation, such as metallic sheathed cable, rubber insulation, and wire wrapped with polyethylene, may have specific applications but do not match the widespread use and versatility of Romex in typical residential environments.