How can you identify aluminum wiring in your home? Residential wiring is generally hidden behind walls and within an outer jacket to protect it. Therefore you will need to know where and what to look for.

Does Your Home Have  Aluminum Wiring

First of all, why are you looking for aluminum wiring.  Have you been contacted by your insurance company? Are your neighbours having their aluminum wiring replaced? Both of these are good indicators that you home was built in a time and location where aluminum wiring was used. Aluminum wiring was used by home building contractors in the mid 1960’s to mid 1970’s.  It was considered a good option at the time but has since proved to be a major issue.

Why is Aluminum Wiring Bad?

Over time, aluminum wire connections fail at connections such as outlets, switches and panels. This can lead to fire hazard conditions.  As a result, many insurance companies consider aluminum wiring a liability and require repair before providing coverage. Visit our Aluminum Wiring page for more details on when aluminum wiring was used and why it is so hazardous.

How to Tell if You Have Aluminum Wiring

Most residential aluminum wiring installed was plastic-sheathed or cloth cable (NM type wire, otherwise known as “Romex”). Neither type are easy to tell apart from a copper cable because they look very similar to their copper counterparts. Here are a few ways to identify aluminum wiring:


Look for the printed or embossed markings on the outer insulation, or jacket, of the wires. Residential wires will be visible in unfinished basements, attics, or garages.


Use a flashlight to shine a light on the surface of the wire’s jacket at a low angle to help make the embossed markings easier to see.


Wires with aluminum conductors will have “Al” or “Aluminum” and other information marked every few feet along its length on one side of the wire jacket.

NM type aluminum wiring jacket marked with ‘Aluminum


Note:  Read as much of the marking as possible because you may find a combination of markings. If you find “CU-clad” or “Copper-clad” in addition to “Al” or “Aluminum” on the same wire, this means that the cable uses copper-coated aluminum wire and is still an issue.

Still Can’t Tell If the Wire is Aluminum?

Please contact a qualified electrician if you suspect that you have aluminum wire but you are unable to find identifying marks.  If you do identify aluminum wiring in your home, give us a call at 587-333-3373 or click to find out what repair options are available.

Exquisite Electric offers Free aluminum wiring inspections and repair quotes in the Calgary area.

By: Exquisite Electric

August 17, 2017