Short answer: Homes wired between 1965 and the mid-1970s may have aluminum branch-circuit wiring. CPSC found that homes wired with aluminum before 1972 were 55 times more likely than copper-wired homes to have at least one connection reach fire-hazard conditions (CPSC). CPSC recommends a permanent repair by a qualified electrician.
Check a specific house: Aluminum branch wiring is rated medium for homes built from 1965 to 1975. Open the House Age Decoder with 1970 loaded →
What aluminum branch wiring is
Branch circuits are the wires that run from the panel to outlets, switches and lights. For a period, some builders used solid aluminum wire for these circuits instead of copper. Aluminum is still widely used for large service cables; the concern here is the smaller branch circuits and their connections.
Years used
According to CPSC Publication 516, electrical cables installed between 1965 and the mid-1970s in new homes, additions and rewired circuits may contain aluminum wiring. Homes built before 1965 are unlikely to have aluminum branch wiring, though later additions might.
| Year built | How likely | Notes |
|---|---|---|
| Before 1965 | Unlikely as original | Check any additions or rewired circuits from the period. |
| 1965 to the mid-1970s | Possible (medium) | Not every home from these years has it. |
| Late 1970s and later | Low | Outside the period CPSC’s guidance focuses on; check if unsure. |
Why it worries CPSC
CPSC explains that aluminum connections can deteriorate, increasing electrical resistance, which causes overheating (CPSC). It cites a survey of homes built before 1972 in which aluminum-wired homes were 55 times more likely to have one or more connections at fire-hazard conditions. CPSC also warns that aluminum connections have been reported to fail and overheat without prior warning signs.
How to identify it
- Cable markings: in unfinished basements, attics or garages, look for “AL” or “ALUMINUM” printed or embossed on the outer cable jacket. A flashlight held at a low angle helps (CPSC).
- Read the whole marking: CPSC notes that “CU-clad” or “copper-clad” is copper-coated aluminum, which its repair recommendations do not cover.
- Do not open boxes or panels to check. If you are unsure, CPSC advises having a qualified electrician determine the wire type.
Warning signs
CPSC lists these signs of a possible problem (source):
- Faceplates on outlets or switches that are hot to the touch.
- Flickering lights.
- Circuits that stop working.
- A smell of burning plastic at outlets or switches.
If you notice any of these, have a qualified electrician evaluate the system promptly. The absence of signs does not mean the connections are safe.
What CPSC says about repairs
CPSC recommends permanent repair of aluminum wiring that has not been remediated and strongly recommends hiring a qualified electrician (CPSC). It describes three approaches in general terms:
- Complete replacement with copper wiring.
- The COPALUM crimp connector method.
- An alternative method using AlumiConn connectors.
CPSC calls devices marked CO/ALR an incomplete repair at best, suitable only as an emergency temporary measure, and says twist-on connectors and non-COPALUM crimp connectors are not acceptable permanent repairs. This article does not give installation instructions; all work should be done and inspected according to local rules.
Questions to ask
The home inspector
- Did you see aluminum branch wiring, and on which circuits?
- Did you notice any warm devices, discoloration or signs of past repairs?
- Do you recommend an evaluation by a licensed electrician?
The seller
- Has the aluminum wiring been remediated? Which method, by whom, and is there a permit?
- Were all circuits treated, or only some?
The insurer
- Do you insure homes with aluminum branch wiring?
- What documentation of repair do you need?
Regulators list the condition and age of wiring among premium factors (Connecticut Insurance Department). See home insurance for older homes.
What to do
- Get an evaluation from a licensed electrician familiar with CPSC’s recommended repairs.
- Keep documentation of any remediation for insurers and future buyers.
- If you are buying, get the electrician’s assessment during your inspection period.
- Do not attempt repairs yourself.
Common misunderstandings
- “No problems so far means it’s fine.” CPSC notes connections can fail without warning.
- “New outlets fixed it.” CO/ALR devices are not a permanent repair, according to CPSC.
- “All aluminum wiring is the same problem.” The concern is solid aluminum branch circuits and their connections, not the large service cable.
Why connections are the weak point
Most problems with aluminum branch wiring show up where the wire meets something else: an outlet, a switch, a light fixture, a splice or the panel. CPSC’s focus is on those connections, which is why its recommended repairs all deal with how aluminum is joined, or replace it entirely. Every outlet, switch, fixture and splice on an aluminum circuit is a connection that needs attention in a complete repair, not just the ones that show warning signs.
Quick answers
Is copper-clad aluminum the same thing?
No. CPSC notes that wire marked CU-clad or copper-clad is copper-coated aluminum and is not covered by its repair recommendations. Ask an electrician.
Can I replace a switch myself with an ‘AL’ rated one?
CPSC considers CO/ALR devices an incomplete repair at best and recommends that a qualified electrician do the work. This site does not give electrical instructions.
Will a home inspector catch it?
Many inspectors will note aluminum branch wiring if they see it at the panel or in exposed areas, and refer you to an electrician. Ask directly.
Before-you-buy checklist
- Ask the inspector to check cable markings at the panel and in exposed areas.
- Ask the seller for documentation of any remediation and the method used.
- Get a licensed electrician’s evaluation within the inspection period.
- Ask your insurer early what it requires.
Who to call
A licensed electrician is the right professional for evaluation and repair. Ask whether they are familiar with CPSC’s recommended repair methods, how many connections they expect to address, whether the work needs a permit and inspection, and what documentation you will receive. Keep that documentation for your insurer and for any future buyer.
Aluminum wiring and the rest of a late-1960s house
Homes from the same years can also have lead paint (HUD estimates about 24% of homes built 1960 to 1977 have some, HUD), asbestos-containing floor tiles and textures, and possibly vermiculite in the attic. Run a 1970 house through the decoder to see the full list in one place.
The bottom line
Aluminum branch wiring in a 1965 to mid-1970s home is manageable, but CPSC is clear that it needs a permanent repair by a qualified electrician, not new outlets or quick fixes. Identify it from cable markings, watch for warning signs, get a professional evaluation and keep the paperwork. That protects both the household and your ability to insure and sell the home.
If you are comparing several houses from this era, ask each seller the same questions about wiring, so you can compare remediation status and documentation side by side.
Finally, remember that smoke alarms are your early warning for any electrical fire, whatever the wiring. Make sure they are installed and working, and ask the electrician whether anything else in the panel or circuits deserves attention while they are there.
Related guides
- Knob-and-tube wiring: years used and insurance problems
- Home insurance for older homes
- All Electrical & Heating guides