Aluminum Wire Danger in the Home
by Dan Derkum
Homes built with aluminum wiring are 55 times more likely than those with copper wiring to go up in smoke, and the odds of a fire increase every year.
Aluminum wiring was used in homes from the mid 1960's to the early 1970's (before 1972) and is a potential fire hazard.
According to the U.S. Consumer Product Safety Commission (CPSC), fires and even deaths have been reported to have been caused by this hazard. Problems due to aluminum wiring expansion, micro-fretting (some metals, when they come into contact with each other, form surface oxides over time. These surface oxides can cause mechanical damage and/or deformation of contacts), and arcing at the aluminum wiring connectors, can cause overheating at connections between the wire and devices (switches and outlets) or at aluminum wire splices. The connections can become hot enough to start a fire without ever tripping a circuit breaker!
The photos shown below are not the most dramatic catastrophes linked to fires caused by aluminum wiring. But these are conditions that are found in many homes with aluminum wiring, confirming that this is a real, common, and widespread hazard. When originally built, the home was apparently wired using aluminum wire (“AL” type Romex).
CPSC research shows that “homes wired with aluminum wire manufactured before 1972 are 55 times more likely to have one or more connections reach "Fire Hazard Conditions" than are homes wired with copper.” Post 1972 “aluminum wire is also a concern. Introduction of the aluminum wire "alloys" in the 1972 time frame did not solve most of the connection failure problems.”
Aluminum wiring is still permitted and used for certain applications, including residential service entrance wiring and single-purpose higher amperage circuits such as 240V air conditioning or electric range circuits. The fire risk from single purpose circuits is much less than for branch circuits.
About the Author
Dan A. Derkum is the owner of DAD's Construction, a leading South Orange County, California design-and-build remodeling and renovation contractor.