Copper got expensive in the late 1960s, so for about a decade a lot of homes were wired with aluminum instead. If your Toronto house was built or rewired roughly between 1965 and 1975, there is a fair chance the branch circuits are aluminum. It comes up constantly on resale and insurance.

So is it a problem? Sometimes. The metal is fine. The trouble is at the connections.

Why aluminum connections fail

Aluminum expands and contracts more than copper as it heats and cools. Over years of normal use, that movement can loosen a connection at an outlet, switch or breaker. Aluminum also oxidizes, and that oxide layer adds resistance.

A loose, high-resistance connection heats up. That heat is the actual fire risk, not the wire running through your walls. The warning signs we look for are outlets or switch plates that feel warm, discoloured or scorched device faces, a burning smell, or flickering that traces back to one spot. If you are seeing flicker, that is worth reading about in our post on why lights flicker or dim.

What insurers want to see

Like knob-and-tube, aluminum branch wiring is something many Ontario insurers flag. They usually want proof it has been inspected and made safe by a licensed contractor before they will write the policy.

There are two accepted ways to do that:

  • Pigtailing each connection with approved connectors, so a short piece of copper meets the device instead of the aluminum. This has to be done with the right connectors rated for aluminum, at every outlet, switch and fixture. Done properly across the whole house, it is a real job, not a quick fix.
  • Rewiring the affected circuits in copper, which is the permanent answer and often makes sense if the walls are already open for a renovation.

Either route needs an electrical permit and an ESA inspection so you have the paperwork your insurer and a future buyer will ask for.

What we would not do

We would not just tighten the screws and call it safe, and we would not use standard connectors that are not rated for aluminum. Those are the shortcuts that cause the exact overheating you are trying to prevent. Aluminum work is a place where doing it to code actually matters.

Where to start

If you know or suspect your home has aluminum wiring, the first step is a proper look at the panel and a sample of the connections. We can tell you quickly whether you are looking at a full pigtail job, a partial rewire, or something in between.

Get a free quote and we will assess it before we quote anything.