Aluminum wiring is legal in Ontario but needs the right parts. In an Applewood or Malton home, outlets and switches need aluminum-rated markings, push-in terminals are out, and a licensed electrician should do the work.
Most of Applewood and Malton went up at the right time to have aluminum branch wiring. The City of Mississauga's 2001 census profile for Applewood puts 43.2% of its homes in the 1961-1970 group and another 35.1% in 1971-1980, about 78% in all. Malton's profile shows 31.6% and 39.0%, about 71%. The Electrical Safety Authority (ESA) says homes built from the mid-1960s to the late 1970s may have aluminum wiring, so a lot of these houses sit squarely in that window. Here is what that means when you want to change an outlet, replace a switch or add a light.
First, find out what you have
The year on the house is only a hint, and ESA notes that some homes have a mix of aluminum and copper. Aluminum branch wiring is usually printed on the cable jacket, and it is silver-coloured at the ends rather than copper. Do not pull devices out of the wall to look. A licensed electrician can open the boxes and check, and that is the first step of any assessment anyway.
Why the connections matter, not the wire
ESA says the Ontario Electrical Safety Code permits aluminum wiring, and that the wire itself is safe when it is terminated properly, without damage to the wire, using devices approved for aluminum. The reported problems are at the terminations, where aluminum oxidizes and does not get along with devices made for copper. ESA lists warm cover plates, discoloured switches or receptacles, arcing, flickering lights and the smell of hot plastic as possible signs. It also warns that aluminum-wired connections have been known to fail and overheat without any prior warning, so waiting for symptoms is not a plan.
Outlets and switches: what the marking must say
ESA's table of required markings for devices used with aluminum wiring is short:
- Receptacles rated 20 amps or less: marked CO/ALR or AL-CU.
- Switches rated 20 amps or less: marked CO/ALR.
- Wire connectors used on aluminum: marked AL-CU or CU-AL.
ESA also says that if an earlier owner already swapped an original device for a newer copper-only one, such as a Decora style, that device is not original and is required to be replaced with a copper/aluminum device. The other approved route is a copper pigtail: a short copper wire joined to the aluminum conductor with a marked connector, so the device itself only touches copper. ESA notes that pigtailing can use up box space, and a surface-mounted extension box may be needed where the old box is too small.
Why push-in terminals are out
Many modern outlets and switches have small holes in the back where you push the wire straight in. ESA says plainly that devices with push-in terminations shall not be used with aluminum conductors. If you or a previous owner replaced a device with a budget one and the wires go into the back, that connection needs fixing. Aluminum is also softer than copper, so nicks and crush spots at a termination create weak points.
Adding pot lights to an aluminum-wired circuit
ESA's table says a light fixture or lampholder needs no special marking on the fixture itself, but approved wire connectors are required. In practice, a new pot light on an aluminum-wired circuit comes down to the connections: the splices must use connectors marked AL-CU or CU-AL, and the switch controlling the lights, if it is replaced, must be marked CO/ALR. A new pot light also adds connections to a circuit, which is one more reason to have the existing ones assessed first. Our guide to pot light retrofits covers the rest of that job.
Insurance and the ESA certificate
ESA says many insurers will not provide or renew coverage on a home with aluminum wiring unless the wiring is inspected and repaired or replaced as necessary, the work is inspected by ESA, and a copy of the certificate of inspection goes to the insurer. In some cases the insurer may require replacement with copper. Requirements differ, so ask your broker what they accept in writing before work starts. ESA recommends a Licensed Electrical Contractor who knows the special techniques aluminum needs, and says to keep the certificate for your records.
Quick answers
Does my Applewood or Malton house have aluminum wiring?
It might. ESA says homes built from the mid-1960s to the late 1970s may have it. The City's 2001 census profiles put most Applewood and Malton homes in 1961-1980.
Can I swap an aluminum-wired outlet for a regular one?
No. ESA says replacement receptacles on aluminum wire must be marked CO/ALR or AL-CU, and switches CO/ALR. Ordinary copper-only devices are not approved for aluminum conductors.
Can I add pot lights to a circuit with aluminum wiring?
Yes, if the connections are made properly. ESA says the fixture needs no special marking, but the wire connectors must be approved and marked AL-CU or CU-AL.
Are push-in terminals allowed on aluminum wire?
No. ESA says devices with push-in terminations shall not be used with aluminum conductors. That means the holes in the back of many outlets and switches are off limits.
Does my insurer need an ESA inspection for aluminum wiring?
Possibly. ESA says many insurers will not provide or renew cover unless the wiring is inspected, repaired as needed and ESA-inspected. Ask your insurer what it requires. If your home needs an assessment, you can get a fixed price from Rhodex.
Before you change a single outlet
Do not buy replacement devices off the shelf and swap them yourself. Have the wiring assessed, call your insurer, and let a licensed electrician decide between marked devices and pigtails. That order keeps you from paying twice.
Related reading
- More home repair guides for Mississauga
- What Should I Fix First in a 1970s or 1980s Erin Mills or Meadowvale Home?
- Electrician services from Rhodex: get a fixed price
- Pot Light Retrofit Cost in Richmond Hill
- How Do I Know If a Contractor Is Licensed in Ontario?
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