Aluminum wiring, used in some homes from the mid 1960's to the early 1970's, is a potential fire hazard. The U.S. Consumer Product Safety Commission 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. Property and lives have been lost due to this hazard. Warm cover plates, discolouration of switches or receptacles, flickering lights, or the smell of hot plastic insulation may be evidence of problems related to aluminum wiring. These conditions are found in many homes with aluminum wiring, confirming that this is a common and widespread hazard.
Aluminum Wiring

Causes of Fire

  • Loose Connections: Aluminum wire expansion and contraction cycles cause loose connections and change in shape at screws. Faulty connections can become hot enough to start a fire without tripping a circuit breaker!
  • Overheating and Arcing: This occurs at termination of connections or at aluminum/copper wire splices using unapproved connectors.
  • Corrosion: If aluminum and copper wires are improperly spliced, corrosion can occur as they are dissimilar metals.

Recognizing Aluminum Wiring

Where wiring is visible in the attic or basement, examine the insulation for markings that indicate the use of aluminum, such as “KAISER”, “ALCAN”, “ALUMINUM”, “AL”, “ALUM”, “AC” or “ACM”.

Upgrading Aluminum Wired Homes

  • Rewire: Completely rewire the home with copper. This is strongly recommended as the best and most permanent solution.
  • “Pigtailing”: This eliminates the aluminum wire connection to switches and outlets by splicing in a short length of copper wire. A certified connector must be used. A COPALUM crimping system creates a cold weld between copper and aluminum wire and is regarded to be a permanent, maintenance‐free repair.
  • CO/ALR Outlets: Replace all outlets and switches with those marked with the letters CO/ALR. This greatly reduces the most frequent failures.

Check All Connections

Regardless of the method chosen for dealing with outlets and switches, the aluminum connections in the circuit breaker panel and at all junction boxes and receptacles should be inspected by a licensed Electrician. At the circuit breaker panel, verify that each aluminum wire is coated with corrosion COPALUM crimp & heat‐shrink tube inhibitor. Have your Electrician apply the specified torque to each screw terminal to make sure it has not loosened over time. When re‐making a connection, remember to abrade the wire to remove the aluminum oxide layer and immediately apply additional corrosion inhibitor before re‐connecting any aluminum wire.