Aluminum wiring: what owners of older houses should know
For a stretch of the late 1960s and 1970s, copper prices pushed builders across Canada to wire houses with aluminum. If your house dates from that era, there is a fair chance some or all of its branch wiring is aluminum, and a fair chance an insurer or home inspector will eventually bring it up. Here is the honest version of what that means.
The wire is not the problem. The connections are.
Aluminum conducts electricity fine; utilities use it for service conductors to this day. The trouble in houses shows up at terminations. Aluminum expands and contracts with heat more than copper, oxidizes differently, and creeps under screw pressure over decades. At a receptacle or switch that was never rated for it, that slow loosening becomes resistance, resistance becomes heat, and heat at a connection point is the failure mode everyone is worried about.
That is why the state of an aluminum-wired house depends almost entirely on its connections: what devices were used, whether they were rated CO/ALR for aluminum, and whether anyone has been in the boxes since 1975 doing things they should not have.
What insurers actually want
Most insurers will cover an aluminum-wired house; what they commonly require is an inspection by a licensed electrical contractor and, where needed, remediation with the paperwork to show for it. The letter is usually asking for evidence, not a rewire. An assessment that documents the condition of the connections, corrects the ones that need it, and files the work with the ESA is what closes that conversation in most cases.
What proper remediation looks like
The accepted approaches are specific: devices rated for aluminum at every termination, or copper pigtails joined to the aluminum with connectors approved for the purpose, installed the way the listing requires. What it never looks like is a handful of new receptacles from the hardware store swapped on as-is, which quietly makes things worse by adding unrated connections. This is close, careful, box-by-box work, and it is very much a licensed-contractor job.
A full rewire is the right call in some houses, but it is not the default. The honest sequence is assess first, remediate what needs it, and price a rewire only when the assessment says the wiring itself has been damaged or butchered over the years.
Signs worth acting on
Warm cover plates, flickering that follows one circuit, a faint hot-plastic smell near outlets, or devices that crackle when plugs go in: in any house these deserve attention, and in an aluminum-wired house they deserve it promptly. Absent symptoms, the sensible move is still an assessment when you buy, when you renovate, or when the insurer asks, because the whole subject is cheaper as maintenance than as emergency.