Is aluminum wiring in a house dangerous?

Yes, it can be. Aluminum branch-circuit wiring is not a hazard sitting quietly in the wall; the trouble is at the places where the wire connects. The U.S. Consumer Product Safety Commission (CPSC) found that homes built before 1972, and wired with aluminum, are 55 times more likely to have one or more wire connections at outlets reach "Fire Hazard Conditions" than homes wired with copper.^[1] The good news is that the problem has permanent fixes, and most of them do not mean tearing out your walls.

Why aluminum wiring is a fire risk

The wire itself is not the culprit. There are several deterioration processes in aluminum wire connections that cause increased resistance to the flow of electric current, resulting in damage that is cumulative in effect.^[1] That increased resistance causes overheating, sometimes at hazardous levels, when current is flowing in the circuit.^[1]

In practice that means a receptacle, switch, light fixture or appliance connection can slowly degrade over years, getting hotter each time it carries a load. CPSC's survey looked only at outlets, and it points out that other aluminum connections and splices in a home are also prone to fail.^[1]

Does my house have it?

Age is the first clue. Homes built before 1965 are unlikely to have aluminum branch circuit wiring.^[1] Electrical cables installed between 1965 and the mid 1970s in new homes, in additions, and as part of rewired or new circuits may contain aluminum wiring.^[1] A house from that era may have aluminum on some circuits and copper on others, and an addition can differ from the original house.

The cable jacket tells you for certain. Cable with aluminum conductors will have "Al" or "Aluminum" marked on one side of the cable jacket every few feet along its length.^[1] You can often read it where cable is exposed in an unfinished basement, attic or garage. Do not open outlets or switch boxes to look. If you cannot tell, ask an electrician to identify it.

One caution: copper-clad aluminum cable is not covered by CPSC's repair recommendations.^[1] If the markings include "CU-clad" or "Copper-clad" along with "Al", tell the electrician so the right fix is chosen.

Warning signs, and why their absence is not reassuring

Failing aluminum-wired connections seldom provide easily detected warning signs.^[1] Aluminum-wired connections and splices have been reported to fail and overheat without any prior indications or problems.^[1] So a house with outlets that seem fine can still have a problem.

When there are signs, CPSC lists hot-to-the-touch face plates on receptacles or switches, flickering lights, circuits that don't work, and the smell of burning plastic at outlets or switches.^[1] Treat any of these as urgent: stop using that circuit and call an electrician. For a wider checklist, see warning signs of bad wiring in a house.

What the permanent fixes are

CPSC approves of only three methods for a permanent repair: complete replacement with copper cable, the COPALUM method, and the AlumiConn connector.^[1] Replacing the aluminum with copper removes the cause of the problem. CPSC calls it the best method available, but for many homes it is impractical or prohibitively expensive.^[1]

The connector methods keep the existing wire and repair where it connects. Whichever one is used, the repair should include every connection or splice involving aluminum wire in the home, including outlets, dimmers, switches, fixtures, appliances and junction boxes.^[1] A repair that fixes only the outlets leaves other connections exposed.

Cover-plate swaps, anti-oxidant paste on its own and other quick fixes are not on CPSC's list of permanent methods. If a quote proposes one, ask why.

For what these options cost and what moves the price, read how much it costs to replace aluminum wiring in Virginia.

If you are buying or already own the house

If you own it, you do not need to panic, but you should not ignore it. Ask an electrician to inspect the house, tell you which circuits are aluminum and quote the repair options in writing. Meanwhile, avoid overloading circuits and do not ignore a warm outlet.

If you are buying, treat aluminum wiring as a negotiating and planning point rather than an automatic deal-breaker. Get the electrician's inspection and written quote during your due diligence period, so the repair cost is known before closing.

When to call a licensed pro

For all of it, including the inspection. CPSC says it is highly recommended that you hire a qualified electrician to perform this remediation.^[1] In its warning-signs section it adds that you could be electrocuted, or you could make the problem worse if you try it yourself.^[1]

Virginia law agrees. It defines a tradesman as any individual who does electrical, plumbing or HVAC work for the general public for compensation,^[2] and no individual may work as a tradesman unless licensed.^[3] Check the licence before you hire, and ask the electrician which of the three approved methods they propose and why.

Loclis lists DPOR-licensed electrical businesses with their licence number and class. Browse electrical services or read more electrical answers.

To have an electrician look at your wiring, describe the job once and licensed local electricians quote it.