Aluminum wiring repair for Boston-area houses

Why aluminum branch wiring fails at the joints

Solid aluminum branch wiring went into many houses during a stretch of the mid 1960s and 1970s when copper prices rose. The wire itself carries current fine. The trouble is at the ends: aluminum expands more than copper when it heats, it slowly flows away from screw pressure, and it forms an oxide that resists current. Over years those effects loosen a joint until it runs hot.

You can usually spot it by the printing on the cable jacket in the basement or attic, which reads ALUMINUM or AL, and by the dull silver conductors inside an outlet box. Larger stranded aluminum feeders to ranges or subpanels are a different, more forgiving material and aren't the concern here. The 15 and 20 amp branch circuits to outlets and lights are.

Three ways to deal with aluminum wiring

Pigtailing with rated connectors

Pigtailing joins a short copper lead to each aluminum conductor with a connector listed for aluminum to copper, then attaches the copper lead to the outlet or switch. The methods with a record behind them are a crimp connector installed with its dedicated tool and set-screw connectors rated for both metals. Ordinary twist-on wire nuts are not the fix. The work has to reach every joint in the house, including fixture boxes, the panel and any splices in junction boxes, because one missed connection is still a failure point. It disrupts far less than rewiring, but boxes in older houses are often crowded, and the added connectors need room.

Aluminum-rated devices

Outlets and switches marked CO/ALR are built to accept aluminum wire directly on their screw terminals. They're a better choice than standard devices on aluminum, and they make sense where a box is too crowded for pigtails. They don't address splices inside walls, ceiling fixtures or the panel connections, and the selection is narrow, with few GFCI, dimmer or smart options. For that reason we use them as part of a plan rather than the whole plan. If you only want a few devices replaced, we'll be clear that the rest of the connections remain untreated.

Branch circuit replacement

Replacing aluminum branch circuits with copper removes the issue for good and is the option buyers and insurers most readily accept. It means fishing new cable through finished walls and ceilings, which is more disruptive than pigtailing and takes more planning. We often combine approaches: rewire the circuits that are easy to reach or already part of a renovation, such as a kitchen, and pigtail the rest. That spreads the work out without leaving any aluminum connection untreated. Where the job needs a permit, we file it, and the work is inspected before walls are closed.

What drives the cost of aluminum remediation

Aluminum remediation is priced on how many connections the house has and which method you choose for each circuit.

1. Connection count. Every outlet, switch, fixture and splice is a connection, and a house can have a lot of them.
2. Method chosen. Pigtailing costs less than rewiring, and rated devices fall in between depending on the mix.
3. Box fill. Crowded boxes may need extensions or replacement to fit the added connectors.
4. Hidden splices. Junction boxes above ceilings or behind panels take time to find and reach.
5. Wall finishes. Plaster and finished ceilings make rewiring more involved than open framing.
6. Permit and inspection. Work that needs a permit includes the filing and the inspection visit.

Pigtail, rated devices or new copper

Each method deals with the same problem, with a different balance of disruption and permanence.

Where aluminum turns up in older Massachusetts houses

What a full remediation covers

• A count of every aluminum connection in the house
• Pigtails at outlets, switches and fixtures
• Splices in junction boxes remade with listed connectors
• Panel terminations checked and torqued
• Crowded boxes extended or replaced where needed
• Circuit testing after the work
• A room-by-room record of what was done

How a remediation job runs

1. Confirm and count

   We verify the wiring is aluminum and count every connection, room by room.

2. Choose a method per circuit

   You decide where to pigtail, use rated devices or rewire.

3. Remediate every joint

   Each connection is made with listed connectors and tools, with nothing left untreated.

4. Check the panel

   Aluminum terminations at the breakers are cleaned and torqued properly.

5. Test and document

   Circuits are tested and you get a room-by-room record for buyers or insurers.

Aluminum wiring questions