Aluminum Wiring Hazards home inspectors

Aluminum single strand wiring (10 gauge, rated 20 amps and 12 gauge rated 15 amps), was used from 1965 to 1974 although I have seen a few homes where a few coils of aluminum wiring were used after those dates.

Is aluminum wire a hazard? No it is not. However the connections are a known fire hazard.  When aluminum wiring gets hot it expands, aluminum wiring cools it contracts creating the potential for a loose connection that allows more heat to develop the next time current is drawn on the circuit. 

During home inspections we perform we use a sophisticated electrical testing device that actually puts circuits under a load.  Loose connections, corroded connections and connections that are likely to get hot are frequently found with this special and expensive meter, few inspectors use.  Make sure the inspector you pick is testing for voltage drop as well as the resistance of the wiring at electric receptacles.  While the method we use is far from perfect it is far superior to the cheap 3 light testers required by the very minimal state of NJ standards.   

For those of you who remember high school science when you heat things they usually expand, when they cool they contract.  As aluminum wiring gets hot it expands against the screw that holds it in place, when it cools it contracts and a microscopic gap between the connection and the wire occurs.  Over time the connection oxidizes and develops more resistance and eventually it gets hotter and the gap and corrosion continue to occur.  

Eventually the aluminum wiring connection can get hot enough to ignite inside the wall. A house fire is frequently the result.  Installation of special wire nuts is not a recommended solution because other problems may occur.  A solution that may help is the installation of special crimp on connectors. The AMP Corporation designed a wire crimping tool and system that will provide dependable results with aluminum to copper connections. The crimp is designed to ensure that air does not come between the aluminum and copper. After the connection is crimped, it is covered with a sleeve, which is shrunk around the connection. This process minimizes oxidation at the contact. 

This is the only system that the Consumer Product Safety Commission (CPSC) has accepted. 

1. The CPSC does not recognize any other system or correction as acceptable. This creates legal concerns for anyone who may recommend a different solution. 

2. AMP Corporation does not sell the crimping tool; they have patents pending and only allow users to lease the equipment. This limits access for residential or small work, because it is difficult to justify leasing costs for one home. 

3. The number of “qualified” electricians that have gone through the AMP training creates further limitations. There are very few electricians in the country that have gone through the training and most are commercial electricians. To read the information the CPSC has made available about aluminum wiring go to aluminum wiring.pdf

U.S. books U.K. books Canada books Germany books France books Japan books

File last updated February 08, 2012 * Copyright © 2012 All rights reserved by: Accurate Inspections, Inc. A New Jersey home inspection firm 56 Woodland Drive, Woodland Park (formerly West Paterson) NJ 07424 973-812-5100 providing New Jersey Certified Home Inspections in NJ, by New Jersey Licensed home inspectors. Inspector of record Michael Del Greco, New Jersey Home Inspector License GI 0121.