By Randy Yates, Technical Supervisor and Technical Training Administrator, NPI/GPI Corporate
As we in the home inspection industry know, the discovery aluminum wiring should be noted in a home inspection report. But as a home owner or buyer, you may wonder if there is cause for concern. Aluminum wiring was introduced as a result of a shortage of and escalating costs of copper in the late 1960s up to mid-1970s. It is estimated that aluminum wiring systems were installed in 1.5 million homes, and for these homes aluminum wiring systems are at the end of what is generally considered aluminum’s useful life, which is about 30 years.
In houses with aluminum wiring, some home owners discovered overheating was occurring, and this was attributed to the expansive and corrosive characteristics of aluminum wiring within the circuit connections. As a result, the National Electrical Code (NEC) declared aluminum wiring to be a potential fire hazard, and its use ceased.
The following are signs of premature failure of aluminum wiring observable to a home owner:
- Unusually warm cover plates on switches and outlets
- A burning plastic odor in the vicinity of a switch or outlet
- Sparks, flame, smoke or arcing at switches or outlets
- Flickering lights
- Electrical features and appliances suddenly stop working and no circuit breakers have been tripped
- Incandescent lights momentarily dim or brighten when a motor starts
If you have aluminum wiring in your home, you may wonder whether it is safe, legal or needs to be replaced. Here are some things to consider.
Is Aluminum Wiring Safe?
It can be, if the right components have been installed with the aluminum wiring and the system is in good condition.
Is It Legal?
The electrical codes don’t say that you can’t use aluminum wiring. In fact, it is recognized in the NEC. However, in some areas, insurance companies either won’t cover a house with aluminum wiring or will charge a higher premium to cover it.
Do I Need to Replace Aluminum Wiring in My House?
Maybe not entirely, but maybe in part. It really depends on whether the system is in good condition or you notice any of the signs listed above. However, to be certain the system is safe, you should have it inspected and evaluated by an electrician.
The NEC recognizes the use of aluminum wiring as long as all components used in installing the electrical system and components — switches, receptacles, fixtures and connectors — are rated for use in aluminum electrical wiring systems. Splice connectors also must be rated for use with aluminum wiring. Any component used must have an AL or AL/CU rating. (AL represents aluminum and CU represents copper.)
Only a thorough, invasive inspection — meaning removal of all electrical covers on junction boxes, all outlet and receptacle covers, and all receptacle and switches — can confirm that all components are rated for use in an aluminum wiring system, and this is outside the scope a home inspection.
The bottom line is that whenever a single-strand aluminum electrical system is discovered during the course of a home inspection, the inspector should recommend that the system be fully inspected by a qualified, licensed electrician.