Which type of wiring should an inspector defer for specialist evaluation?

Single strand aluminum wiring is known to have specific safety concerns that warrant a closer inspection by a specialist. In the past, this type of wiring was used extensively in residential applications, particularly during the 1960s and 1970s, but it was later found to have inherent risks, including a higher propensity for overheating and creating loose connections, which can lead to fire hazards.

Aluminum conducts electricity differently than copper and is more susceptible to oxidation. This can result in poor connections, which may not only reduce the efficiency of the electrical system but also pose serious safety risks. Proper installation techniques and specific types of connectors are critical to ensuring that aluminum wiring operates safely and effectively. Moreover, since many insurance companies have additional stipulations or premium increases for homes with aluminum wiring, securing a specialist's evaluation can provide a more thorough assessment of the potential hazards and necessary corrective actions.

In contrast, Romex wiring, knob-and-tube wiring, and Type NM cable are more commonly accepted forms of residential wiring and may not exhibit the same level of immediate risk associated with single strand aluminum wiring. While they also require inspection and may have codes and standards to adhere to, they generally do not require the same level of specialist evaluation as single strand aluminum wiring.