Aluminum Wiring Inspections

Heimer Engineering uses Professional Engineers to perform home inspections,
building inspections, condo inspections, and co-op inspections in Manhattan, Queens,
Brooklyn, Bronx, Staten Island, Nassau, Suffolk, Rockland, Putnam, and Westchester

Aluminum: Atomic number: 13, Atomic mass: 26.98Houses, buildings, condos, and co-ops built between 1964 and 1973 may have branch circuit aluminum wiring.  In 1974, two persons died in a home fire caused by faulty aluminum wiring.  After an extensive investigation of the cause of the fire, the US Consumer Product Safety Commission issued Publication 516, REPAIRING ALUMINUM WIRING.

Aluminum wiring is typically marked with the word ALUMINUM or the symbol AL.  Since most homes initially wired with branch circuit aluminum wiring have had additional wiring installed, it is important to examine visible labeling on the wiring.  However, even a careful examination may fail to turn up the presence of branch circuit aluminum wiring.

The aluminum wiring that is of concern is branch circuit wiring (12 AWG and 10 AWG wire) manufactured before before 1973.  The hazard exists when aluminum wiring is improperly used in devices designed for copper wiring.  Copper-clad aluminum wiring (usually marked CU-CLAD AL or CU-CLAD ALUMINUM) is not considered hazardous.  When this branch circuit aluminum wiring was improperly attached to devices such as switches and outlets that were not designed for aluminum wiring, the junctions can become warm due to a poor connection.  This heating can result in a fire.  Over time, multiple factors cause the risks to increase.

Open electric circuit breaker panelAluminum wiring is commonly used to provide electric power to larger equipment (central air-conditioning compressors,  sub-panel feeders, electric dryers, etc.).  Aluminum wiring is also used to connect the electric meter to the circuit breaker panel, and as the main electric service drop from the power company to a home or building.  Although you may not be able to tell from this photograph, the large wires connected to the circuit breaker at the top of the photograph to the right are aluminum.  You can also see the aluminum neutral wire in the lower right-hand corner of the picture.

Aluminum wiring is widely used in electric power transmission.  Aluminum wiring is found in industrial and other settings where large amounts of wire are needed.  As long as the aluminum wiring is properly installed, it is not hazardous.

Any aluminum wiring manufactured in the United States after the early 1970s is likely of a different alloy than the hazardous aluminum wiring, and is at a lower fire risk than the earlier residential aluminum wiring.  If the computer that you are reading this Web page on is plugged in, it is receiving electric power that is being transmitted through aluminum wiring.

Branch circuit aluminum wiring in homes

Exposed wiringMost houses that were originally wired with branch circuit aluminum wiring have had an extensive amount of copper wiring added.  It is often virtually impossible to find the aluminum wiring unless the house is completely vacant.  Because so much copper wiring has been added, the old method of opening a few boxes and looking for aluminum wiring often fails to find the aluminum wiring.  Even opening a circuit breaker panel may fail to find aluminum wiring in a rewired house.

Open electric circuit breaker panelIf the house you are purchasing was built between 1964 and 1973,have a Licensed Electrician remove the covers from the outlets and switches, and look for branch circuit aluminum wiring.  Unfortunately, this may not be possible until after you own the house.  This is because finding the branch circuit aluminum wiring requires opening multiple electrical boxes, many of which are blocked by furniture during the pre-purchase inspection.

The old trick of opening circuit breaker panel (which a Home Inspector should never do for safety reasons) often fails to find aluminum wiring.  In any house that has been renovated or extensively rewired, it may not be practical to locate aluminum wiring during a pre-purchase inspection.

If the house is wired with Romex® and was constructed between 1964 and 1973, it may have aluminum wiring.  A house wired with metal-armored cable is unlikely to have branch circuit aluminum wiring in.  Since the use of Romex® is limited in the City of New York, you very rarely find branch circuit aluminum wiring in homes within the City of New York.

Historical Note:  Aluminum (and steel) wiring was reportedly used in some homes during World War II due to the copper shortage.  If aluminum or steel wiring was used, it is rare and there are no reported incidents of problems with this wiring.  The rumors of wartime aluminum and steel wire are likely based on homeowners who were unable to obtain copper wire, and improvised with whatever metal was available.

Danger!Only a Licensed Electrician should open a circuit breaker or fuse panel because of the associated risks.  An Inspector or anyone else who is not a Licensed Electrician should never open a circuit breaker or fuse panel.

A Licensed Electrician is in the position to correct hazardous conditions created by opening the circuit breaker or fuse panel.  Someone who is not a Licensed Electrician lacks the experience to deal with hazardous conditions that might develop as a result of opening a circuit breaker or fuse panel.  If a problem develops because of opening the panel (for example, a circuit breaker becomes loose), the Inspector is not in a position to safely resolve the problem.  Thus, opening a circuit breaker or fuse panel could create a hazardous condition.

Most communities require electricians to be licensed, and prohibit anyone other than a Licensed Electrician from performing electrical work.  (Exceptions are made for homeowners wiring their own home.)  So a home inspector who is not a Licensed Electrician is not permitted to open an electrical panel.

An experienced Engineer Inspector can determine the condition of the wiring by visual examination.  The question you should ask is why do some home inspectors insist on opening the circuit breaker panel when it could create a hazard?  Can't these home inspectors find risks and hazards by examining the way the building is wired?  Are these home Inspectors missing problems because of their limited abilities?  Are these home inspectors missing serious wiring problems because of their narrow focus?