Aluminum Solid Strand Branch Wiring
"The U.S. Consumer Product Safety Commission (CPSC) staff and other government officials have investigated numerous hazardous incidents and fires throughout the nation involving aluminum branch circuit wiring.
In North American residential construction, aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices. Aluminum was widely used for electrical devices (outlets, switches, lighting, fans, etc.) and other equipment bath fans, and some appliances such as dishwashers. I have a realtor friend that had her entire house repaired except the dishwasher which caught fire. Aluminum single or solid strand wiring was used for #12, and #10 general-purpose branch wiring.
Aluminum wiring was used in the 1960s-1970s for the wiring of receptacles, switches, and devices throughout the house. Single-stranded branch aluminum wiring has been implicated with fires in houses at the point of connection. Aluminum does not conduct electricity as efficiently as copper and creates more resistance and therefore heat. The wire expands and contracts more than copper resulting in loose connections between wires or device connections. The problem was compounded by screw heads that were too small for the devices, i.e., receptacles, switches, lights, etc. This is where a short can occur as oxidation builds up between the aluminum wires, or copper and aluminum, and pose a potential risk of fire. According to CPSC, they recommend improvements such as the following: Installing or verifying proper UL-listed or nationally approved connections by the CPSC at all devices, junction boxes, and equipment throughout the house.
It is recommended evaluation of all connections and all devices, junction boxes, and equipment throughout the house. This should be conducted by an electrician specializing in aluminum wiring repair and follow approved or recognized methods such as the Consumer Product Safety Commission recommendation. Failure to comply or utilizing improper repair methods could pose a serious fire and safety hazard. Some electricians are utilizing unapproved methods which could be more of a fire hazard. Be sure the electrician submits the methods of repairs along with documentation to verify the methods they are using are approved by the CPSC and the locations of all repairs in a room-by-room “journal”. Some methods recently approved are no longer acceptable according to the Consumer Product Safety Commission such as the Ideal 65 Wire Nuts and AL/CU or COALR-rated devices. https://www.cpsc.gov/s3fs-public/516.pdf
1) Complete Replacement of Copper Cable
2) COPALUM Method of Repair
3) Acceptable Alternative Repair
4) Method/AlumiConn Connector
Stephen Lee Showalter, NACHI® CMI, ASHI ACI
Home Inspector, Environmental Consultant
Maryland State Home Inspector License #29634
ASHI ACI Certified Membership
NACHI® CMI Certified Master Inspector
InterNACHI® CPI Certified Membership
Certified Commercial Property Inspector Association
FAA Certified UAS Pilot #3987636
CRT Certified Residential Thermographer
Showalter Property Consultants providing quality home inspections and environmental testing throughout Maryland since 1988. For a quality home inspection contact us on schedule online.