Aluminum wiring scares buyers out of good houses every month in the GTA — usually unnecessarily. We've remediated hundreds of these homes. Here's the honest picture.
The actual risk, without the drama
Between roughly 1965 and 1976, copper prices pushed builders to aluminum branch wiring. The problem was never the wire itself — it's the connections. Aluminum expands and contracts more than copper with each heating cycle, slowly loosening terminations at outlets, switches, and fixtures. Loose connections arc, arcing makes heat, and heat starts fires. US data from the era found homes with original aluminum connections had meaningfully higher fire risk than copper homes — at the connections, not along the wire.
That distinction is why remediation works. Copper pigtailing — joining a short copper lead to each aluminum conductor with an approved connector (AlumiConn or COPALUM) at every single termination — addresses the failure point directly. The Electrical Safety Authority recognizes it as a permanent fix. A typical GTA home runs $2,500–$5,000 for complete pigtailing with ESA inspection and the documentation insurers require (cost details here).
The insurance reality — handle it before closing
Insurance, not fire, is what actually derails purchases. Most Ontario insurers will not write a new policy on un-remediated aluminum wiring, or will exclude electrical claims. Since proof of insurance is required to close a mortgage, an aluminum-wiring surprise discovered late can genuinely threaten your closing date. The sequence that works: identify the wiring during your inspection period, get a written remediation quote (we provide them within 24 hours), confirm with your insurer that pigtailing-plus-ESA-certificate satisfies them, and either negotiate the price down by the quote amount or schedule remediation for the week of possession.
The pre-closing checklist
One: a proper pre-purchase electrical inspection — not just the home inspector's visual pass. We open the panel, identify aluminum on every circuit, and check for the era's other common issues (undersized 100A panels, ungrounded outlets, DIY add-ons in finished basements). Two: written quotes for everything found. Three: your insurer's requirements in writing. Four: a negotiation number backed by documents instead of fear.
Bought the house already? Don't panic — schedule remediation rather than living with original connections indefinitely, and avoid heavy loads on suspect circuits in the meantime. Warm cover plates, flickering, or a hot plastic smell mean call immediately: 416-837-4038, any hour.