Aluminum Wiring – Real Estate Inspections

• The type of branch wiring installed. Is it Copper, Tin Coated Cloth (another potentially adverse wire), Solid Aluminum or Knob and Tube (usually older and adverse)
• The type of Panel, is it one with Breakers, Fuses or something else
• Defects within the panel, wiring defects, fire hazards, proper grounding and more

Below is an article taken from Nachi.org and it’s a good one!

Homes and structures built between approximately 1965 and 1973, can have single-strand aluminum wiring, as it was sometimes substituted for copper branch-circuit wiring in residential electrical systems due to the sudden escalating price of copper. After a decade of use by homeowners and electricians, inherent weaknesses were discovered in the metal that lead to its disuse as a branch wiring material, it is used in a stranded for larger circuits/appliances, even today. Although properly maintained aluminum wiring is acceptable, aluminum will generally become defective faster than copper due to certain qualities inherent in the metal. Neglected connections in outlets, switches and light fixtures containing aluminum wiring become increasingly dangerous over time. Poor connections cause wiring to overheat, creating a potential fire hazard. In addition, the presence of single-strand aluminum wiring may void a home’s insurance policies, you should check with your insurer. Inspectors may instruct their clients to talk with their insurance agents about whether the presence of aluminum wiring in their home is a problem that requires changes to their policy language, Inspectors will also inform client to have electrical system reviewed by an electrician as needed.

Aluminum possesses certain qualities that, compared with copper, make it an undesirable material as an electrical conductor. These qualities all lead to loose connections, where fire hazards become likely. These qualities are as follows:

• higher electrical resistance. Aluminum has a high resistance to electrical current flow, which means that, given the same amperage, aluminum conductors must be of a larger diameter than would be required by copper wiring/conductors.
• less ductile. Aluminum will fatigue and break down more readily when subjected to bending and other forms of abuse than copper, which is more ductile. Fatigue will cause the wire to break down internally and will increasingly resist electrical current, leading to a buildup of excessive heat.
• galvanic corrosion.  In the presence of moisture, aluminum will undergo galvanic corrosion when it comes into contact with certain dissimilar metals.
• oxidation. Exposure to oxygen in the air causes deterioration to the outer surface of the wire. This process is called oxidation. Aluminum wire is more easily oxidized than copper wire, and the compound formed by this process – aluminum oxide – is less conductive than copper oxide. As time passes, oxidation can deteriorate connections and present a fire hazard.
• greater malleability. Aluminum is soft and malleable, meaning it is highly sensitive to compression. After a screw has been over-tightened on aluminum wiring, for instance, the wire will continue to deform or “flow” even after the tightening has ceased. This deformation will create a loose connection and increase electrical resistance in that location.
• greater thermal expansion and contraction. Even more than copper, aluminum expands and contracts with changes in temperature. Over time, this process will cause connections between the wire and the device to degrade. For this reason, aluminum wires should never be inserted into the “stab,” “bayonet” or “push-in” type terminations found on the back of many light switches and outlets.
• excessive vibration. Electrical current vibrates as it passes through wiring. This vibration is more extreme in aluminum than it is in copper, and, as time passes, it can cause connections to loosen.
• All of these are good reasons to make sure your home inspector is able to handle these tasks. I’m certified, qualified and professional.

Identifying Aluminum Wiring – A good Home Inspector should be able to identify this type of Wiring.

• Aluminum wires are the color of aluminum and are easily discernible from copper and other metals.
• Since the early 1970s, wiring-device binding terminals for use with aluminum wire have been marked CO/ALR, which stands for “copper/aluminum revised.”
• Look for the word “aluminum” or the initials “AL” on the plastic wire jacket. Where wiring is visible, such as in the attic or electrical panel, inspectors can look for printed or embossed letters on the plastic wire jacket. Aluminum wire may have the word “aluminum,” or a specific brand name, such as “Kaiser Aluminum,” marked on the wire jacket. Where labels are hard to read, a light can be shined along the length of the wire.
• When was the house built? Homes built or expanded between 1965 and 1973 are more likely to have aluminum wiring than houses built before or after those years.

Options for Correction

Aluminum wiring should be evaluated by a qualified electrician who is experienced in evaluating and correcting aluminum wiring problems. Not all licensed electricians are properly trained to deal with defective aluminum wiring. The CPSC recommends the following two methods for correction for aluminum wiring:

• Rewire the home with copper wire. While this is the most effective method, rewiring is expensive and impractical, in most cases.
• Use copalum crimps. The crimp connector repair consists of attaching a piece of copper wire to the existing aluminum wire branch circuit with a specially designed metal sleeve and powered crimping tool. This special connector can be properly installed only with the matching AMP tool. An insulating sleeve is placed around the crimp connector to complete the repair. Although effective, they are expensive (typically around $50 per outlet, switch or light fixture).
• Ultimately, your Home Inspector needs to be educated in means of identifying these items… I am, is your home Inspector?

Although not recommended by the CPSC as methods of permanent repair for defective aluminum wiring, the following methods may be considered:

• application of anti-oxidant paste. This method can be used for wires that are multi-stranded or wires that are too large to be effectively crimped.
• pigtailing. This method involves attaching a short piece of copper wire to the aluminum wire with a twist-on connector. the copper wire is connected to the switch, wall outlet or other termination device. This method is only effective if the connections between the aluminum wires and the copper pigtails are extremely reliable. Pigtailing with some types of connectors, even though Underwriters Laboratories might presently list them for the application, can lead to increasing the hazard. Also, beware that pigtailing will increase the number of connections, all of which must be maintained. Aluminum Wiring Repair (AWR), Inc., of Aurora, Colorado, advises that pigtailing can be useful as a temporary repair or in isolated applications, such as the installation of a ceiling fan.
• CO/ALR connections. According to the CPSC, these devices cannot be used for all parts of the wiring system, such as ceiling-mounted light fixtures or permanently wired appliances and, as such, CO/ALR connections cannot constitute a complete repair. Also, according to AWR, these connections often loosen over time.
• alumiconn. Although AWR believes this method may be an effective temporary fix, they are wary that it has little history, and that they are larger than copper crimps and are often incorrectly applied.
• Replace certain failure-prone types of devices and connections with others that are more compatible with aluminum wire.
• Remove the ignitable materials from the vicinity of the connections.

In summary, aluminum wiring can be a fire hazard due to inherent qualities of the metal. Inspectors should be capable of identifying this type of wiring.

Steps to take as a Home Buyer –

• Ensure that you are hiring a qualified, thorough Home Inspector.
• If recommendations are made, make sure you follow them. Some of these are important as they may affect the health and safety of the occupants.