While the hazards associated with aluminum branch circuit conductors in homes have been known about for the last 40 years, there still seems to be a lot of disagreement about what should be done when aluminum branch circuit conductors are found during a home inspection. I'm writing this post to give advice to anyone in Minnesota planning to buy a home with aluminum branch circuit conductors.
For the record, "Aluminum branch circuit conductors" refers to wires that provide power to 15 and 20 amp circuits in houses. It's the wire that connects to outlets, switches, lights, and the like. For the rest of this blog, I'm going to call it aluminum wiring, but I'm not referring to the aluminum wiring that is commonly used on 240 volt circuits or service drops on today's homes. That stuff is fine.
Just in case you're unfamiliar with aluminum wiring, here are a few key points:
I've never inspected a home that was actually on fire because of poor connections at the aluminum wiring, but I've seen a few that looked like they were close.
There's a persistent myth that if a home was wired with aluminum over 40 years ago and it hasn't burned down yet, it's never going to. Of course, that's just plain silly.
While there are plenty of houses with aluminum wiring that haven't started on fire, this doesn't mean they're safe. The current occupants haven't burned the house down, but when the new owners move in, will they put different demands on the system? Of course. With a change in occupancy comes a change in use, and that's when problems often show up.
If you're buying a home with aluminum wiring, my advice is to have a thorough inspection of the wiring performed by an electrician and repairs made if needed. This inspection would require the inspection of at least a representative number of connections. This means pulling outlets out of the wall, pulling switches out of the wall, taking lights down to inspect the connections, pulling wires out of junction boxes, etc. If any connections aren't proper, repairs should be made.
The CPSC lists three potential repairs for homes with aluminum wiring: individual repairs with COPALUM connectors, individual repairs with AlumiConn connectors, or complete replacement of the aluminum wire. You can read about how the individual repairs would be made here - Aluminum Wiring Repairs.
Individual repairs with COPALUM connectors is not a viable option for Minnesotans. This requires the use of a specialized product that needs to be installed with a specialized tool, by a certified COPALUM Retermination Contractor. I contacted the company that provides this product, and was informed that there is not a single certified contractor in Minnesota. So that's out.
It's possible to make individual repairs with AlumiConn connectors, but those connectors are ridiculously expensive. Amazon currently sells them for $3.26 each, plus shipping & handling. That's $3.26 for a single wire nut. Yikes. If you buy in bulk, you can buy a 1,000 pack for $2.59 each.
Besides the fact that this repair method would be very expensive, there's a chance that the repairs would be incomplete. Would every single junction box be found? Maybe, maybe not. Seattle home inspector Charles Buell shared a story about a year ago where he was called back to verify repairs were made at a home that he had previously inspected, and he found at least one junction box that had been missed. You can read about about it here - incomplete aluminum wiring repairs.
The surest and most complete repair is to have the aluminum wiring replaced. This leaves very little to chance, and doesn't leave the home with a bunch of repair methods that the next semi-qualified homeowner might accidentally mess up. The obvious drawback to this is the expense involved. Of course, the expense depends on how much aluminum wiring is present and will vary greatly from house to house. This is where the electrician comes in.
If you're buying a home with aluminum wiring and you hire an electrician to inspect and/or repair the wiring, make sure they have experience with aluminum wiring repairs. We had a young electrician recently ask us how he was supposed to repair the aluminum wiring in a house. Our advice was to partner up with an electrician who had experience doing this work.
For a more detailed discussion regarding the specific hazards with aluminum wiring, here are some excellent related documents:
Reuben Saltzman, Structure Tech Home Inspections