Aluminum wiring was used from 1965 until 1972 in some homes in our area due to a severe shortage of copper. Originally considered a safe and economical substitute for copper wire, aluminum was used throughout the country. The aluminum wire used at the time soon developed problems. Its use was discontinued in residential branch wiring for 15 and 20 amp circuits in 1972.
The Southwire Company improved the properties of aluminum wire and it is currently used in modern aircraft and industrial applications. Aluminum wire is used almost exclusively for utility company transmission lines and service entry wire.
Only single strand Aluminum wiring is considered unsafe under normal conditions. Stranded aluminum is used in wire sizes 8 and larger in commercial applications. Due to the bad experiences of the earlier period aluminum branch wiring is seldom found in residential construction after 1972.
Aluminum wiring from 1965 to 1972
Our concern is focused on residential wiring installed from 1965 to as late as 1975. Numerous reports of solid strand aluminum wiring overheating and causing fires have been reported. The problem appears to be aluminum’s tendency too expand and contract with different current loads.
Problem areas are most often found in receptacles, switches and light fixtures. As a result the CPSC investigated and recommends a qualified electrician evaluate all aluminum single strand circuits.
The picture below shows the difference between aluminum and copper wire. The aluminum wire will appear soft and silver colored while the copper wire will be brownish red (copper colored). When visible the outer jacket on the aluminum wire will be marked as aluminum.
In the late 1940’s and 50’s some copper wire was “tinned” in an attempted to prevent corrosion. This wire will usually have a woven cloth like outer jacket and is not aluminum. This may cause confusion and a qualified electrician can quickly verify if it is aluminum or copper.
What if My House Has Aluminum Wiring
The fact that your home contains aluminum wiring does not necessarily indicate an immediate problem. However the US Consumer Product Safety Commision (CPSC) reports:
“A national survey conducted by Franklin Research Institute for CPSC showed that homes built before `1972 (‘old technology aluminum wire’) are 55 times more likely to have one or more wire connections reach “Fire Hazard Conditions ” than is a home wired with copper.” https://www.cpsc.gov//PageFiles/118856/516.pdf
Consumer Product Safety Council Recommendations
The CPSC recommends using a properly trained licensed electrician to inspect and repair residential aluminum wiring. There are many opinions on the proper was to correct aluminum wiring problems; here is what the CPSC recommends:
- Complete Replacement with Copper Cable. Replacement of the aluminum branch circuit conductors with copper wire eliminates the primary cause of the potential hazards, the aluminum wire itself.
2. COPALUM Method of Repair. As an Alternate to rewiring with copper, CPSC recommends attaching a short section of copper wire to the ends of the aluminum wire at connection points (a technique commonly referred to as “pigtailing”). Using a special connector named COPALUM to join the wires. CPSC staff considers pigtailing with a COPALUM connector to be a safe and permanent repair of the existing aluminum wiring.
3. Acceptable Alternative Repair Method. CPSC staff recognizes that copper replacement may be cost prohibitive and the COPALUM repair may be unavailable in a locality. Based upon an evaluation that was supported by the CPSC, the AlumiConn connector may be considered the next best alternative for a permanent repair. If the COPALUM repair is not available,
The CPSC continues to explain these are the only methods they approve for repairs. The use of twist on wire nuts or hardware store style crimp connectors are not to be used. Only a qualified electrician should attempt aluminum wire repairs.
Most of all, it is important to remember safety is always our most important goal. This is not a “Home Owner” or “Handyman” repair, aluminum wiring repair should be left to experienced and qualified electricians with special tools and training.
If you do have aluminum wire new receptacles and switches that are rated for use with copper and/or aluminum wiring are available, A qualified electrician should be employed to make these changes.
Hawley Home inspections LLC is a Veteran owned and family operated company. We have been serving the St Louis metro area and Southern Illinois since 2010.