How Does How Old Your House Is Affect Your Electricity?

Grounding

• The grounding of electric circuits by including an extra wire on all fixtures that connects directly to earth is a safety feature required by the National Electric Code. Many houses built in the mid-20th century and before lack this feature and the switches, outlets and light fixtures can all become energized by loose connections or worn insulation. When you touch an ungrounded fixture that has become energized in this way, you can get a shock as the electricity uses your body as a path to the ground. The shock can be severe if your feet are unprotected or you are standing in water.

The Service Panel

• Besides being ungrounded, service panels in houses built before 1950 use fuses instead of the circuit breakers found in more contemporary ones. A fuse is basically a metal connector that melts when the current passing through it exceeds its rating. Unlike the tripping of a circuit breaker, the process isn't instantaneous, and a current surge can continue to do damage for a short time until the melting is complete. Moreover, fuses cannot be reset like breakers. If one blows, you won't have power in the circuit it was protecting until you find a suitable replacement.

Aluminum Wiring

• Many houses built from the mid 1960s to the mid 1970s were wired with aluminum cables, and aluminum wiring has since proven to be hazardous. It tends to deteriorate over time, and as it does, its electrical resistance increases and it overheats. This effect is most often noticed in light fixtures, switches and outlet, where the cables connect to the fixture terminals. The high heat can melt plastic and cause fires. Unless you replace all the wiring in the house, fixing aluminum wiring isn't a simple job and usually must be done by an electrician with a license for making such repairs.

Wear and Tear

• The older your house is, the more likely it is that wiring insulation may be cracked, worn or damaged by pests. As a result, one or both of the wires in a cable may become exposed, presenting a danger of shock or short circuit. Age and corrosion can also cause lights and outlets to malfunction. Moreover, older houses are more likely to have shoddy or improper repairs, such as wire connections left dangling in the walls, wire sizes mixed in a circuit or poorly-planned circuits that overload the fuse and cause frequent outages.