Does your home have aluminum wiring? What you need to know

Do you have an older home? If your home was built between the mid-'60 to mid-'70s, it may have aluminum wiring rather than the standard copper which is equipped in most new homes.

Aluminum wiring isn't a hazard in itself, but when receptacles, conductors, switches, etc. not intended for use with aluminum wiring are installed, the threat of a hazard is possible. Why? Aluminum has a much higher rate of thermal expansion than the connection on the switch or receptacle, which makes it possible for it to expand and deform. This can lead to a loose connection and, under the right electrical load conditions, could cause sparking, overheating, or even a fire.

How do I know what wiring I have?

Take a look at the electrical wiring, either between the open floor joists, in the basement, up in the attic, or at the service panel. If the wiring is aluminum and manufactured before May 1977, the outer covering of the cable will be marked with the word ALUMINUM, ALUM or AL at least every 12 inches. If the cable was manufactured after May 1977, the marking may be ALUMINUM ACM, ALUM ACM, or AL ACM.

What types of receptacles/conductors can be used?

When replacing devices that will go with aluminum wiring, look for those bearing the marking "CO/ALR". This means "Copper Aluminum Revised" to differentiate these devices from earlier models. The CO/ALR marking identifies the equipment as having been tested and found suitable for use with aluminum or copper wiring by the Canadian Standards Association (CSA), a standards organization whose certification is accepted by inspection authorities across Canada. Never use devices that do not have this marking as problems with overheating may occur, which could lead to fire, as took place for this

What are the danger signs to watch for?

  • Excessive heating of the outlet
  • Sparking
  • Popping sounds
  • Smell of smoke

If you are concerned about wiring in your home, contact a licensed electrical contractor and have them take a look. Also, don't forget to look into getting the appropriate Electrical permits for any work. 


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