During a period in the late 1960s and early 1970s, copper prices spiked and aluminum wiring was widely used as a substitute for branch circuit wiring in residential construction. Homes built during this period throughout the Twin Cities — including many in the first-ring suburbs like Fridley, Brooklyn Park, Coon Rapids, and parts of Minneapolis — may have aluminum branch circuit wiring in some or all of their circuits.
What the Problem Is
Aluminum wiring itself isn't inherently dangerous. The problem is at the connections — outlets, switches, light fixtures, and the panel. Aluminum expands and contracts more than copper when it heats and cools. Over thousands of cycles, connections can loosen. Loose connections arc, and arcing is a fire hazard. The U.S. Consumer Product Safety Commission has found that homes with aluminum branch circuit wiring are significantly more likely to have electrical fire conditions than those with copper.
How to Tell If You Have It
The wiring itself is silver-colored rather than the orange-copper color of copper wire. You may also see markings on the outer jacket of the cable — aluminum wiring from this era is often marked "AL" or "ALUM." If your home was built between 1965 and 1973, it's worth having a licensed electrician check.
The Solutions
There are two main approaches to addressing aluminum wiring:
- Pigtailing with CO/ALR connectors: Each outlet and switch connection is pigtailed — a short piece of copper wire is connected to the aluminum with a specific connector rated for aluminum-to-copper connections (CO/ALR rated), and the device is then connected to the copper pigtail. This is approved by CPSC as an acceptable remediation and is the most common approach. It requires using CO/ALR-rated devices throughout, and the work is labor-intensive but doesn't require any new wiring.
- Full rewire: All aluminum branch circuit wiring is removed and replaced with copper. The most comprehensive solution — eliminates the aluminum entirely — but significantly more involved and expensive.
Insurance Implications
Many homeowner's insurance carriers ask about aluminum wiring during the application process and may decline to write a policy, surcharge the premium, or require remediation documentation for homes with untreated aluminum wiring. If you're buying or insuring a home with aluminum wiring, this is worth addressing proactively.
Hawkins Electric assesses and remediates aluminum wiring throughout Minneapolis, St. Paul, and the Twin Cities. Call us to schedule an inspection.