Aluminum Wiring Pigtails – What You Should Know

Aluminum wiring pigtails safeguard against the risk of fire in homes where aluminum wired homes show indications of failure and overheating at termination points.

Aluminum wiring was widely used in Canada from the mid-1960s through the 70s. It was favoured over copper wiring because it’s a good conductor of electricity and was cheaper at the time. Some houses are still wired with aluminum or a combination of aluminum and copper.

Aluminum wiring pigtails fix the potential problem of overheating that arises from weaker connections and/or the use of incompatible devices.

aluminum wiring pigtail

What is Pigtailing Aluminum Wiring?

Pigtailing aluminum wiring entails splicing a short length of copper wire to aluminum wire and then connect the copper wire to the electrical device approved for copper connection.

The proper connectors must be used – approved for copper to aluminum connections – and antioxidant compounds.

The antioxidant compound is used to avoid the risk of the aluminum becoming corroded. Aluminum is prone to oxidation over time.

Because it contracts and expands more than copper, it can also result in a loose connection.

Loose or corroded connections increase electrical resistance, which can radiate enough heat to melt fixtures and insulation.

Mismatched devices and fittings can also cause overheating.

A loose connection also poses the risk of sparking, which can ignite nearby combustible material including wall insulation, the wiring insulation itself, and wallpaper.


Is Pigtailing Aluminum Wiring Safe?

Aluminum wiring pigtails will make your home safer when installed by a professional electrician. However, a DIY attempt at pigtailing aluminum wiring is likely to make matters worse.

Ensuring connections are safe and do their job properly calls for expertise and painstaking attention to detail.

Aluminum is softer than copper, and meticulous care is needed to avoid damage such as nicks, cuts or hairline cracks, which can cause overheating. Special techniques are required for working with aluminum wiring, including aluminum wiring pigtails.

For instance, the antioxidant compound is conductive and needs to be used sparingly, with the removal of any excess material. And if there’s not enough room in an existing outlet box, a new surface-mounted extension may be needed for new connectors.

Pigtailing aluminum wiring is safe as long as proper terminals and connections are made – without damaging the wire – and with materials approved by the Canadian Electrical Code.

Aluminum wiring pigtails approved by the Electrical Safety Authority are the most common solution for making aluminum wiring safe.

identify aluminum wiring

How Can I Tell Whether My Home Has Aluminum Wiring?

More than 450,000 homes in Canada are estimated to have aluminum wiring.

If you’re unsure whether your home has aluminum wiring, you can check for certain markings on the cables between open floor joists, in your basement or attic, or at the electrical service panel.

If aluminum wiring was installed in your home before May 1977, the cables will be labelled at least every 12 inches as ALUMINUM, ALUM, or AL.

If the wiring was fitted after May 1977, it may be tagged as ALUMINUM ACM, ALUM ACM, or AL ACM.

British Columbia Electrical Safety Authority says signs of a problem with aluminum wiring include:


Warming of faceplates on receptacles or switches.

Odd smells near switches or receptacles.

Persistent flickering of lights.

Unusual TV or radio static interference.


Do not wait for indications of overheating of the connection or warning sign of arcing within switches and receptacles.

Aluminum wiring may also be dangerous without any noticeable signs, which is why the Electrical Safety Authority strongly advises eliminating the hazard by replacing the original electrical devices with aluminum approved ones rated or have aluminum wiring pigtails installed.

It’s also recommended to have aluminum wiring systems inspected every four or five years.

aluminum wiring pigtails

Aluminum Wiring Safety Concerns

The main cause of electrical fires in Canada is defective wiring, and the danger of fire is regarded as much greater in homes with aluminum wiring.

For example:

The International Association of Certified Home Inspectors says several aspects of aluminum make it potentially dangerous as an electrical conductor.

Vancouver-headquartered Square One Insurance Services says that where aluminum and copper wiring have been combined in homes, it presents an extreme hazard in the absence of the correct connectors.

The Electrical Safety Authority reported in June 2019 that concerns about the safety of aluminum wiring were increasing.

Because of the potential fire hazard, you may find difficult to insure your home if it has aluminum wiring.


Why You Need a Licensed Electrician for Aluminum Wiring Pigtailing

Pigtailing aluminum wiring provides a popular alternative to the more expensive option of a complete rewiring job.

The BC Safety Authority says a licensed electrician is needed for pigtailing aluminum wiring to avoid further problems by ensuring all connections are terminated correctly.

A qualified electrician can make your home safer by installing aluminum wiring pigtails that conform to all safety regulations and codes. For example, a proper join between copper and aluminum wires is essential to avoid separation of the connection.

An electrical contractor experienced in aluminum wiring repairs, with expertise in the special techniques necessary for working with and repairing aluminum wiring should inspect the electrical terminations and where issues are found the damaged aluminum conductor must be cut back to remove the damaged wire and then the necessary repairs made.