Older homes in many parts of Canada still contain aluminum wiring. While this material was widely used during the 1960s and 1970s, safety concerns and modern electrical standards have since raised questions about long-term performance and fire risk.
For homeowners and commercial property managers considering replacing aluminum wiring, the options often narrow down to pigtailing or complete replacement. Understanding each approach’s differences, risks, and benefits can help determine the right path forward.
Aluminum wiring reacts differently than copper, especially when stressed by high current or repeated expansion and contraction. Over time, this can result in loose connections, arcing, and excessive heat buildup, which increase the chance of electrical fires and other hazards.
While newer homes avoid aluminum entirely, thousands of buildings across Ontario and the Greater Toronto Area still rely on outdated wiring. For any property with this wiring, choosing between pigtailing and complete aluminum wiring replacement requires close inspection and understanding the current electrical code requirements.
Pigtailing refers to connecting a short length of copper wire to existing aluminum wire using an approved connector, typically at outlets, switches, and fixtures. The copper segment then connects to the device terminal. This method allows the aluminum wiring to remain inside the walls while the copper performs the final leg of the electrical path to devices and switches.
Electricians must use specific connectors and approved methods, including proper torque and anti-oxidation compounds, to reduce resistance and heat buildup. Pigtailing can offer a safer interface between outdated aluminum and modern copper terminals when executed properly. However it is always better to note that pig-tailing is a temporary solution and has to be redone every 5-10 years depending on usage.
Pigtailing presents some practical advantages. The most significant appeal is cost. Completely replacing aluminum wiring can be disruptive and expensive, especially in well-furnished spaces. Pigtailing avoids opening walls and ceilings, making it more convenient for homeowners and building managers. When performed to code, it also aligns with insurance requirements.
However, this approach does have limitations. The original aluminum wiring remains in place within walls and ceilings and may still be subject to oxidation, thermal cycling fatigue, or mechanical degradation over time. The effectiveness of pigtailing depends on correct installation using approved aluminum-to-copper connectors—such as AlumiConn, COPALUM, or twist-on connectors specifically rated for AL-CU connections—as well as the use of anti-oxidant compound and proper torque. If the existing conductors show signs of excessive wear, corrosion, or heat damage, pigtailing may not adequately address the long-term safety risks, and a full wiring replacement may need to be considered.
Aluminum-wiring replacement involves disconnecting all active aluminum conductors, cutting and terminating them so they cannot be reconnected, and rewiring the property’s circuits with copper. Unless full interior renovation is in progress, only the visible and accessible aluminum wiring is physically removed—conductors hidden behind finished walls are safely decommissioned and left in place.
This method eliminates compatibility issues and aligns with current electrical safety standards. It’s often the preferred solution when the existing aluminum wiring shows significant corrosion, overheating, or widespread deterioration.
While more costly and time-intensive than pigtailing, full replacement provides a long-term upgrade. It can also improve property value and simplify future electrical work. So, where building renovations already involve open walls or complete system upgrades, full replacement becomes the most practical choice.
Both methods—pigtailing and full aluminum wiring replacement—have practical applications depending on the building’s age, condition, and layout. The key lies in assessing each installation individually, with a licensed electrician reviewing the wiring for heat marks, brittle connections, or signs of oxidation. Budget, insurance concerns, and renovation plans all factor into the decision.
A good starting point for those unsure where to begin is learning how to identify aluminum wiring issues. Outlets and switches that feel hot or lights that flicker often indicate old aluminum wiring-related issues behind the wall.
Schedule a wiring replacement or repair today with Canadian Wire Wizards to determine the safest next steps for your property.