Aluminum wiring in a 1960s or 1970s Northern Virginia house: fix the wiring first, then talk about sprinklers

A lot of the calls we get from Reston, Dale City, Sterling Park, and the older streets of Springfield and Annandale start the same way. A buyer’s inspector wrote “aluminum branch circuit wiring observed” on the report, the insurance company asked about it on the application, and somewhere in that week somebody said the word sprinklers. The instinct is right. The order people want to do it in is usually wrong. This article covers what the wiring problem actually is, what fixes it, what a 13D sprinkler system does and does not do about an electrical fire, and how to run both jobs so the walls open once.

What the aluminum wiring problem is

From about 1965 to 1973 copper got expensive and builders ran aluminum wire for the ordinary 15 and 20 amp circuits, the ones that feed outlets, switches, and lights. Aluminum expands and shrinks more than copper every time a circuit heats and cools, it creeps out from under a screw terminal over the years, and the oxide that forms on it does not conduct well. A connection that was tight in 1970 is loose now. A loose connection heats, and it heats inside a box behind a cover plate, in the wall, where nobody sees it. The Consumer Product Safety Commission studied this in the 1970s and found connections in aluminum wired houses reach fire hazard conditions far more often than copper ones.

The problem is the small solid wire, not the big stuff. Aluminum service entrance cable and the heavy feeders to a range or a dryer are still installed today and are fine when they are terminated right. Look at the cable jackets in the panel or in the attic. The ones that matter are printed AL or ALUMINUM, and the exposed conductor is silver instead of copper colored.

The signs a homeowner notices are warm cover plates, lights that flicker when a vacuum starts, a smell of hot plastic near an outlet, a breaker that trips with nothing much plugged in, and discoloration around receptacle slots.

Which houses have it

Reston from Lake Anne through the sections finished in the early 1970s, Dale City, Sterling Park, and the ramblers, splits, and colonials of the same years in Springfield, Annandale, Woodbridge, and Herndon. Townhouses from those years too. Burke Centre and almost everything in Ashburn came later and were wired in copper. A 1971 house that has been “updated” can still have it behind the new outlets, and a new receptacle rated for copper only, screwed onto an aluminum wire, is worse than what the builder installed.

The fixes, in the order electricians rank them

1. Rewire. Copper everywhere. Walls and ceilings get opened, an electrical permit is pulled with the county, and the house is a job site for a while. It is the only fix that removes the aluminum instead of managing it.
2. COPALUM crimp. A copper pigtail cold welded to the aluminum at every connection with a special tool, by an installer certified to use it. CPSC calls it a permanent repair. Fewer electricians around here offer it than you would expect.
3. AlumiConn connectors. A set screw lug joins a copper pigtail to each aluminum wire. CPSC lists it as an acceptable alternative to the crimp. Every box in the house gets opened, which is hundreds of connections in a colonial.

Two things that are not a fix. Twist on wire nuts between copper and aluminum, even the ones sold for it, are not recommended by CPSC. Swapping outlets for devices marked CO/ALR helps at that device and does nothing at the splices in the ceiling boxes and junction boxes you cannot see.

While the electrician is there, look at the panel. The same years produced panels whose breakers are known for failing to trip, and an inspector who sees one of those brand names will write it up right under the wiring. A panel replacement is a utility disconnect, a county inspection, and a day without power, and it is the right time to add the circuit a monitored sprinkler alarm will want later.

What a sprinkler does about an electrical fire

Sprinklers do not prevent fires. A 13D system is built to control a fire that has already started long enough for everyone to get out, and the sprinkler myths article explains why that is usually one head, not twenty. An electrical fire starts inside a box, in the wall. The head in the room opens when the air at the ceiling reaches the bulb rating, which the temperature ratings article puts at 155°F for an ordinary head. That means the fire has come out of the wall and into the room before the head does anything. The outlet face is burning, the curtain above it has caught. At that moment the head does exactly what it is for. It holds the fire to that corner, keeps the room survivable, and buys the minutes between the smoke alarm and the front door.

The gap is the attic. Junction boxes for ceiling lights and the splices from an old addition sit up there, and under 13D the attic has no heads, covered in the rooms without sprinklers article. A fire that starts at an attic splice burns above the sprinklered space until it comes through a ceiling. That is the whole argument for doing the wiring first. The repair removes the cause the sprinkler cannot reach. The sprinkler then covers the connection the electrician missed, the lamp cord, the space heater, and the kitchen.

Doing both jobs in the right order

• Rewire plus sprinklers. The electrician opens the walls and ceilings. Our mains and branch lines go through the same openings, usually in the same week. One drywall patching bill instead of two moves the retrofit toward the low end of the $2 to $7 per sprinklered square foot range, for the reasons the retrofit cost article lays out.
• Connector repair plus sprinklers. The walls stay closed for the electrical work, so the sprinkler job is an ordinary retrofit, and the retrofit by house style article shows what that looks like in each kind of house.
• Two permits, two inspections. The electrical permit and the fire protection permit are separate applications in every Northern Virginia county, covered in the permit timeline article. The drywall closes after both rough in inspections pass, not after the first one.
• Monitoring. If you want the flow switch tied to an alarm company, the monitoring article explains the panel and the circuit it needs. Have the electrician leave that circuit while the walls are open.

Insurance and resale

Carriers ask about aluminum wiring on the application, and some want a repair letter from a licensed electrician before they will write the policy. The sprinkler system is a separate line on the same application, and the insurance discount article covers what Virginia carriers do with it. Send both letters. The acceptance comes from the wiring repair, the credit comes from the sprinklers.

When you sell, the buyer’s inspector will write up aluminum wiring every time it is still there, and a repair receipt tied to a closed electrical permit is what closes that item. The sprinkler system shows up on the same report, and the selling article covers what the inspector looks at on the riser.

What we look at on the estimate visit

We are not electricians and we do not pretend to be. On a house from these years we read the panel label, look at the cable jackets in the attic while we are up there measuring, and check whether a monitored alarm has a circuit to land on. If nobody has had an electrician look at the wiring, we say so before we talk about pipe. The rest of what the visit covers is in the estimate visit article.