Spurred by the growth of consumer products and housing markets in the 1950’s and 60’s the cost of copper skyrocketed. This promoted the widespread use of Aluminum in residential homes worldwide. Speaking of the Calgary market many popular communities such as Pump Hill, Bayview, Lake Bonavista, Varsity, Silver Springs and Palliser where primarily built using Aluminum wiring. The two most common questions clients ask are “Is it safe? Should it be replaced?” The short answer is that it is safe and does not need to be replaced immediately. However here are the implications of aluminum wiring.
The Issues/ Making of the Myth
Shortly after the residential adoption of aluminum wiring became popular issues started to arise. Most commonly warm cover plates on switches and receptacles, singed insulation on wiring and flickering of lights. These issues where caused by the overheating of wires at the plugs, overheating can mean fires and fires unless used for marshmallows are scary. An investigation was launched and the conclusion is that there were three major practical differences between copper and aluminum.
- Softness: Aluminum is a softer metal than copper. Therefore different connectors at the plugs would have to be used to prevent the damaging of the wires. It was the damaging of the wires that caused the hot spots that could lead to fires.
- Loosening of the wires: Electrical current generates heat when it travels through wire. Since Aluminum is softer it expands more than copper would when it is warm. The larger size of the expansions and contractions sometimes would cause the wires to creep away from the connections. The poor contact on the connections would cause the lights to flicker.
- Rusting: When copper rusts the greenish oxidant still conducts electricity pretty well. Whereas the white oxidant of aluminum does not. This leads to once again the flickering of lights and potential hot spots.
All three of these issues are connection based. The solution which happened early one in the installation of such wiring was to use connectors that were made with aluminum in mind. The vast majority of homes where constructed with the proper connectors or have changed out the older copper only versions over the last 40 years. It is still very important to use a home inspector that has knowledge of the different connectors or to bring a journeyman electrician to such properties before completing the sale. However from a safety and practicality standpoint if a house has the proper connectors there is no difference to copper.
Why the Stigma still exists
The fact that there is a stigma around aluminum wiring is what I would argue from a real estate professional point of view is the biggest issue with buying a home with such wiring. If there wasn’t a stigma you wouldn’t be reading this article of mine! Essentially the presence of the stigma has the ability to negatively affect the marketability of your home. My advise to sellers is to get ahead of the stigma by addressing it in marketing materials in the home. Place a disclosure of the proper connectors (If you know you have them) on the electrical panel so potential buyers are aware that you know of the wiring and have made it safe.