Aluminum Wiring - What's The Risk?

The History:

From the mid 1960s to the mid 1970s, with copper prices skyrocketing due to high demand and limited supply, builders and electricians in Calgary and area turned to a more cost-effective alternative: aluminum wiring.

Aluminum conductors were already being used for high-voltage installations, so it seemed like a logical alternative for residential wiring. Aluminum wiring met Canadian electrical codes at the time, and from roughly 1965 to 1976, Calgary electricians wired homes using aluminum. Dalhousie, Varsity, Marlborough, Oakridge, and Willow Park are among some of the Calgary neighbourhoods where homes were wired with aluminum.

However, by the mid-1970s, builders and electricians began phasing out aluminum in favor of copper due to rising safety concerns.

The Problems:

The safety concerns stemmed from issues with overheating at device termination points—meaning where the wiring connects to a receptacle, switch, or fixture. Over time, these connections could become loose. Aluminum expands and contracts more than copper, and this constant movement leads to loosened connections.

Loose connections cause arcing, overheating, and eventually pose serious fire hazards.

Aluminum is also susceptible to oxidation. A layer of aluminum oxide forms on the conductor, increasing resistance, which then increases heat.

Another issue is that aluminum is softer than copper. If not installed properly, it can deform under screw pressure, leading to weak connections.

Devices such as receptacles, switches, and breakers must be rated for aluminum terminations. Many times, homeowners unknowingly increase the risk of electrical hazards by replacing the old AL rated devices with modern tamper-resistant Decora-style devices—which are usually copper-only rated.

After seeing a pattern of higher fire claims and liability from homes wired with aluminum, insurance companies began to refuse coverage unless remediation was done.

The Solution:

Of course, a complete rewire with copper wiring is the most permanent and safest option. Not only does it eliminate future risks associated with aluminum, but it also satisfies all insurance companies—no questions asked. That said, it’s a very invasive and expensive form of remediation and is best paired with large-scale renovations.

The most common and affordable method of aluminum wiring remediation that insurance companies recognize is copper pigtailing. This involves splicing a short piece of copper wire to the existing aluminum wiring. The connection must be made using AL/CU-rated wire nuts and a deoxidizing compound. The copper pigtail is then connected to a copper-rated device.

Light fixtures are also inspected to ensure the wire connectors are approved for aluminum-to-copper connections.

Conclusion:

If your home was built between 1965 and 1976, there’s a real chance it has aluminum wiring. That doesn’t mean it’s unsafe—but it does mean it needs attention. Loose connections, outdated devices, and improper repairs can increase the risk of electrical failure or fire.

Whether you're looking to remediate for insurance, planning a renovation, or just want peace of mind, it’s important to work with licensed electricians who know how to properly address aluminum wiring.

As licensed Calgary electricians, Sunshine Electric Services is your go to provider for dependable and professional aluminum wiring repairs and remediation.

Call today and let our experienced team shine a light on quality service.