I want to replace the outdated aluminum wiring in my home, but I'm concerned about doing it safely. Aluminum wiring requires special precautions to avoid fires and electrocution. Here is a comprehensive guide on how I can safely replace aluminum wiring in my home.
Dangers of Aluminum Wiring
Aluminum wiring was commonly installed in homes built between 1965 and 1973. Compared to copper wiring, aluminum is more likely to overheat, arc, and melt which can lead to electrical fires.
The main risks of outdated aluminum wiring are:
Overheating - Aluminum expands and contracts more than copper. This can loosen connections and cause wires to overheat.
Arcing - Aluminum oxidizes over time, creating a non-conductive coating. This can cause arcing, sparks, and fires.
Melting - Aluminum melts at a lower temperature than copper. Overheated connections can melt and ignite fires.
These risks are exacerbated by improper installations and outdated wiring devices. Frayed wires, loose connections, and faulty outlets increase fire hazards.
Why Copper Wiring is Safer
Copper is the safest option for residential electrical wiring because:
It has higher heat resistance than aluminum. Copper melts at 1981°F vs 1220°F for aluminum.
It is less prone to oxidation and corrosion over time. Copper forms a patina while aluminum oxidizes.
Copper is a better conductor. It has about 60% higher conductivity than aluminum.
Copper is more ductile. It can be bent and shaped without cracking or breaking.
Replacing outdated aluminum wiring with new copper wiring eliminates fire risks and improves conductivity.
Preparing for an Aluminum Rewire Project
Before starting an aluminum rewire, I need to take several preparatory steps:
Consult an electrician - Only a licensed electrician should replace wiring. I'll get quotes from 3-4 local electricians.
Check insurance coverage - I'll call my home insurance company to see if they require copper rewiring for continued coverage.
Inspect the electrical panel - I'll have an electrician inspect the condition of my electrical panel and recommend upgrades if needed.
Create a rewire plan - The electrician will produce a circuit-by-circuit plan detailing all the wiring that needs replacement.
Get necessary permits - Electrical permits from the city are required for rewiring projects.
Clear access to wires - I'll remove obstructions like insulation and drywall so wires are easily accessible.
Proper planning and preparation will ensure my aluminum rewire project goes smoothly and safely.
How to Rewire with Copper
The basic process for replacing aluminum wiring with copper is:
1. Turn Off Electricity and Install New Panel (If Needed)
The power must be shut off at the main breaker before any work can begin. If the electrical panel needs an upgrade, the electrician will install a new copper bus panel.
2. Access the Wiring
Walls and ceilings may need to be opened to access hidden wires. The electrician will remove drywall, insulation, etc. to reach all the outdated aluminum wiring.
3. Replace Branch Circuits with Copper
The electrician will remove aluminum wires exiting the panel and replace them with new copper branch circuits. All accessible aluminum wiring will be removed.
4. Install Copper Pigtails
Any wiring that remains inaccessible will be fitted with copper pigtails. These short copper wires are connected to aluminum wires to eliminate unsafe connections.
5. Replace Devices with CO/ALR Models
All outlets, switches, and fixtures will be replaced with devices labeled CO/ALR. These are designed for use with both copper and aluminum.
6. Repair Walls, Ceilings, and Floors
Once rewiring is complete, drywall, insulation, and other removed building materials will be replaced and repaired.
7. Restore Power and Test Circuitry
The main power can be turned back on once the electrician verifies all connections are secure.Circuit testing will check for faults.
Cost to Replace Aluminum Wiring
The cost to rewire an average home with copper wiring ranges from $8,000 to $15,000. Factors impacting the cost include:
Home size - More wiring to replace in larger homes
Accessibility - Removing and replacing drywall, insulation, etc. adds labor costs
Electrical panel - Upgrading the panel to accept copper adds $1,000 or more
Number of circuits - More individual branch circuits takes more time to rewire
Electrician rates - Rewiring is complex so expect $50 to $100 per hour
Materials – Copper wiring is expensive, plus new outlets, switches, etc.
Rewiring is a major project, but it’s worthwhile to eliminate fire risks from outdated aluminum wiring.
Can Aluminum Wiring Be Made Safe?
While rewiring with copper is ideal, there are less expensive ways to make aluminum wiring safer. However, these come with some drawbacks:
Pigtails - Copper pigtails Help but leave some aluminum.
CO/ALR outlets - Special outlets reduce arcing but aluminum is still present.
Repair damaged wires - Doesn’t address wires in good condition that could still overheat.
Deox - Applying a coat of deox grease reduces oxidation but has to be reapplied.
Arc-fault circuit breakers - Help detect dangerous electrical arcs but don't prevent them.
Rewiring the entire home with copper remains the best permanent solution. But budget-friendly options can provide an interim safety improvement. An electrician can advise on the best approach.
Safely Working with Existing Aluminum Wiring
If rewiring the entire home with copper isn't feasible, I can take steps to manage the safety risks of aluminum wiring:
Avoid overloading circuits - Don't plug too many appliances into one outlet to prevent overheating.
Check for hot outlets - Unplug appliances and feel for heat which can indicate loose wiring.
Inspect wires - Watch for cracking, oxidation, kinks, or fraying in wires.
Clean connections - Use emery cloth to clean corrosion off wire terminations.
Keep connections tight - Periodically check outlets, switches, etc. and re-tighten terminal screws as needed.
Have an electrician make CO/ALR upgrades - Use specialty outlets and switches designed for aluminum.
Consider AFCI circuit breakers - These help protect against dangerous arcing faults.
While aluminum wiring can never be entirely without risk, proper maintenance and CO/ALR upgrades can reduce hazards until rewiring is possible.
Is Aluminum Wiring Still Used?
Due to the risks associated with residential use, pure aluminum wiring is no longer allowed by the National Electrical Code (NEC) for branch circuits in homes. However, modern AA-8000 series aluminum alloy wire is permitted.
Advantages of AA-8000 alloy aluminum:
Formulated with small amounts of calcium, magnesium, and silicon to increase strength
Utilizes superior installation standards from the 1970s NEC code
Requires compatible connectors and terminations rated CO/ALR
Has more flexible wire strands to prevent cracking at bends
When properly installed, new aluminum alloy wiring is considered safe for residential use. But pure aluminum wiring has long been banned from building codes.
- Outdated aluminum wiring can be a dangerous fire hazard due to overheating, arcing, and melting. Copper wiring is the safest option.
- Replacing all accessible aluminum wiring with new copper branch circuits is the best permanent solution.
- Less expensive alternatives like pigtails and CO/ALR outlets can provide interim improvements only.
- Proper maintenance and avoiding overloads reduces risks if aluminum wiring remains.
- New aluminum wiring is safer but the old type should be fully replaced with copper whenever feasible.
Rewiring a home with copper wiring is a major undertaking. But it provides substantial safety benefits by eliminating the significant risks posed by outdated aluminum wiring. With careful planning and the expertise of a licensed electrician, I can have peace of mind knowing my home's electrical system is safe and reliable for the long-term.