About aluminum wiring

What are the concerns? What you should know.  (Updated 11/2/2022)

What are the concerns?

A majority of property and casualty (P&C) insurers decline applications to insure, or renew insurance policies on residential properties with aluminium wiring.

While it is estimated there are over 450,000 homes in Canada wired with aluminium, these systems are not necessarily problematic, given proper installation and maintenance.

Is there aluminum wiring in the house?

Well, if you weren’t told, you can probably check some of the wiring yourself. This can be done by looking at the wiring between the open floor joists in the basement, in the attic or at the service panel. The outer covering of the cable is often marked with the word ALUMINUM or an abbreviation (AL) every few inches. Your home inspector should be able to make a more detailed assessment.

If you find the wiring installed for lights and wall plugs is aluminium, it is recommended that “CO/ALR” devices be used for replacement of switches and receptacles. Devices other than switches and receptacles, which are suitable for use with aluminium wire, will bear the marking CU-AL.

​Aluminum wiring is safe if properly installed.  

In 1977 the Government of Ontario established a Commission of Inquiry on the use of aluminium wiring in the home. Following a thorough investigation, which included hearings and testimonies conducted over a period of 18 months, the Commission recommended that aluminium wiring should continue to be authorized for residential use.

The Good News

Thankfully, for homebuyers who are faced with uncertainty obtaining insurance on homes with aluminium wiring, a number insurance companies will offer a grace period after possession, if a home inspection has been completed and there are no visible defects or deficiencies related to the electrical system. 

More often, insurance companies will require that a further inspection be completed prior to closing by a licensed electrician, or by the “local authority having jurisdiction.” This service was previously offered performed in Ontario by the Electrical Safety Authority (ESA) however discontinued in 2021 because aluminium wiring is not an Ontario Electrical Code issue. Check with your insurer to confirm their requirements, and if acceptable within the terms of your home insurance policy, locate a licensed, certified electrician who can evaluate your house wiring. Among insurers willing to underwrite homeowner policies for houses with aluminium wiring, the annual premiums are comparable to homes with copper wiring. 

On the other hand, insurance coverage at regular rates is difficult to obtain for vintage “knob & tube” (which is copper) wiring, and most often homeowners are obliged to upgrade at least the accessible portions of the wiring within the first month of occupancy.

The Ontario Electrical Safety Code does not impose a legal requirement to upgrade or replace aluminum wiring.

From the ESA: What You Should Know About Aluminum wiring