How to Wire Your Home With Aluminum Wiring

As a homeowner, I've learned that aluminum wiring requires special attention if I want my home's electrical system to be safe and reliable. Here is my guide on everything you need to know about aluminum home wiring.

What is Aluminum Wiring?

Aluminum wiring became popular in homes built between 1965 and 1973 because it was cheaper than copper wiring. Aluminum is just as good at conducting electricity as copper, but it has some important differences:

• Aluminum is lighter and more malleable than copper. This makes aluminum wires more likely to sag and loosen over time.
• Aluminum expands and contracts more with temperature changes. This can loosen connections and cause wires to overheat.
• Aluminum corrodes more easily when in contact with certain materials. Corrosion increases electrical resistance which can cause overheating.

These factors mean that aluminum wiring requires more care and maintenance than copper to operate safely.

Dangers of Aluminum Wiring

If not properly installed and maintained, aluminum wiring can present serious fire and shock hazards:

• Loose connections can generate excessive heat that can melt insulation and surrounding materials. This is the most common cause of fires with aluminum wiring.
• Corroded connections can also cause dangerous overheating. This increases fire risk and can cause dimming lights, tripping breakers, and appliance malfunctions.
• Loose wiring can arc when current flows, increasing fire risk. These arcs can also gradually carbonize connections, increasing resistance and heat generation.

It's essential to follow safety guidelines to minimize these risks if your home has aluminum wiring.

Inspecting Your Home's Wiring

If your home was built between 1965-1973, it's likely it has aluminum wiring. But it's a good idea to inspect your electrical system to confirm:

• Check the main electrical panel - aluminum wiring will be marked AL or aluminum.
• Remove outlet and switch plate covers to observe the conductor metal color - aluminum is not copper colored.
• Examine the insulation thickness - aluminum wire is larger than copper due to lower conductivity.

Document all locations where you find aluminum wiring and note any signs of damage, corrosion, overheating, or melted insulation.

Upgrading with Copper Pigtails

The recommended solution is to connect aluminum wires to short copper "pigtails" at outlets, switches, and fixtures. This isolates the aluminum.

Follow this procedure:

1. Turn off power and remove the outlet, switch, or light fixture.
2. Clean the wires with sandpaper and coat with anti-oxidant paste.
3. Attach a short 6-8 inch copper pigtail using special connectors rated for copper-aluminum.
4. Secure the copper pigtail to the outlet or switch.
5. Carefully fold wires into the electrical box before reinstalling it.

Use pigtails for any new wiring connections too.

Other Safety Tips

Beyond pigtailing, there are other important safety measures to follow:

• Use only switches and outlets labeled CO/ALR for aluminum compatibility.
• Apply antioxidant paste to all aluminum terminations.
• Ensure wires are securely fastened with proper connectors sized for aluminum. Tightness should be confirmed with a torque wrench.
• Avoid high-wattage loads on aluminum circuits. Distribute loads across multiple circuits.
• Circuit breakers must be rated to handle aluminum wiring amp capacity.

Regularly inspect all electrical connections and terminate or pigtail any corroded or overheated wires. With diligent maintenance and the right equipment, aluminum wiring can be used safely. But if in doubt, consult with an electrician. Replacing aluminum wiring completely with copper is also an option, but it’s costly.

Warning Signs of Unsafe Wiring

Watch for these signs of loose connections and have an electrician inspect:

• Flickering lights
• Frequently tripped circuit breakers
• Unusually warm outlets or switches
• Burning odor from fixtures or outlets
• Discolored wires or melted insulation
• Shocks from appliances/fixtures

If you see these, shut off power and call an electrician immediately. Electrical fires spread rapidly so early detection is crucial.

Hiring an Electrician

Due to the risks of improper repairs, always hire a licensed electrician experienced with aluminum wiring for upgrades and pigtailing. Get multiple quotes and verify they are experienced with CO/ALR outlets and pigtailing before hiring.

Check qualifications carefully - aluminum wiring requires expertise to handle safely. Don't attempt DIY repairs unless you are totally confident in your electrical abilities.

Is Aluminum Wiring Always a Problem?

Installed correctly using the right equipment, aluminum wiring can provide safe, reliable electrical power. But it does require more vigilance than copper to operate safely long-term.

Pay attention to the warning signs and have your wiring periodically inspected by a qualified electrician. With proper maintenance and pigtailing, aluminum home wiring can be safe. But upgrading to copper is the best way to minimize risk if budget allows.