Rewiring a home can seem like a daunting task, especially if you don't have any prior electrical experience. However, with the right planning, precautions, and tools, even beginners can successfully rewire their home safely.
In this comprehensive guide, I'll walk you through the entire process step-by-step, from understanding home electrical systems, to developing a rewiring plan, to selecting the right materials and tools, to following proper safety procedures. By the end, you'll have the knowledge and confidence to tackle basic home rewiring projects yourself.
Understanding Home Electrical Systems
Before beginning any electrical project, it's important to understand the basics of how home electrical systems work. Here's a quick overview:
The Main Electrical Service Panel
The main service panel is the central hub that connects your home to the main power supply from the utility company. This panel contains:
Circuit breakers - These shut off power to individual circuits if they become overloaded.
Main service wires - These thick wires deliver power from the utility transformer to your home's circuits.
Neutral and ground wires - These provide return paths for electricity back to the transformer.
A main breaker - This shuts off all power to the home.
Branch circuits distribute electricity throughout your home. Most branch circuits are 120 volts and are protected by a 15 or 20 amp circuit breaker in the main panel. Common branch circuits include:
General lighting circuits - Supply power to light fixtures.
Appliance/receptacle circuits - Supply power to wall outlets.
HVAC equipment circuits - Supply power to heating/cooling systems.
Electrical Wiring and Devices
Within the walls, cables distribute power from the panel to devices:
NM (nonmetallic) cable - This flexible cable with insulated wires is run inside walls and ceilings.
Electrical boxes - Outlets, switches, and fixtures mount to these. Boxes contain wire connections.
Conduit - Rigid metal or plastic tubing that protects wires. Used for exposed wiring.
Developing a Rewiring Plan
Careful planning is crucial when rewiring a home. Follow these steps to develop a complete rewiring plan:
Evaluate Your Electrical Needs
Consider how your home's electrical needs may have changed:
Are more circuits needed to support additional appliances and devices?
Are any circuits overloaded, tripping breakers often?
Are any areas underserved by too few outlets?
Choose a Scope of Work
Decide how much you want to rewire:
A total rewire replaces all wiring. Very labor intensive.
A partial rewire updates just certain circuits. Good for overloaded or underserved areas.
Or simply run new circuits to add outlets and lights in remodeled rooms.
Create a Home Electrical Plan
Sketch out a home electrical plan that maps:
Locations of the main service panel and all branch circuits.
The routes for running new wiring to devices.
Any changes to box and outlet/switch locations.
Types and ratings for all new circuits, wiring, and devices.
Having this detailed plan is extremely useful during the rewiring process.
Choosing the Right Electrical Materials
For a safe, durable rewiring job, select the appropriate gauge and type of wiring and upgrade key equipment:
Use copper NM (nonmetallic) cable rather than aluminum - it's safer and more reliable. Choose the right gauge for each circuit based on the amperage rating and length. Common gauges are:
#14 wire for 15 amp general lighting/receptacle circuits.
#12 wire for 20 amp appliance/kitchen/bathroom circuits.
#10 wire for 30 amp HVAC equipment circuits.
GFCI (Ground Fault Circuit Interrupter) Receptacles
Install GFCI receptacles in bathrooms, kitchens, basements, garages, and outdoor areas to prevent dangerous shocks.
AFCI (Arc Fault Circuit Interrupter) Breakers
Use AFCI breakers for bedroom circuits to prevent fires caused by damaged/arcing wires.
Add a whole house surge protector at the main panel to protect electronics from power spikes.
Use sturdy plastic or metal electrical boxes to contain connections. Avoid weak plastic handy boxes.
Acquiring the Right Tools
Rewiring requires some specialized electrical tools for safety and efficiency:
Voltage tester - Checks for live power in wires and boxes. Crucial for safety.
Wire stripper - Quickly strips insulation off ends of wires.
Lineman's pliers - Twists wires together securely and snips wire cleanly.
Fish tape - Tapes used to route new wiring through walls and ceilings.
Cable ripper - Splits apart NM cable down its length to access the bundled wires inside.
Hammer drills - Drills holes through studs for running wiring.
Wire connectors - Twists wires together securely inside boxes. Get lever type for easiest use.
Many more tools like ladders, drywall saws, stud finders, and clamp meters may be useful as well. Invest in quality to make the job easier.
Following Proper Safety Procedures
Safety should be your top priority. Follow these guidelines to avoid electrical hazards:
Turn Off Power and Verify
Turn off power at the main breaker before starting any electrical work. Verify it's off by testing wires with a non-contact voltage tester.
Use Personal Protective Equipment
Always wear rubber-soled shoes, safety goggles, and electrical gloves when handling wires.
Connect Green/Bare Ground Wires First
Ground wires stabilize electrical currents and prevent shocks. Connect them first when wiring devices or boxes.
Keep Wires Neat and Tidy
Neatly bundle and clamp wires inside boxes to prevent loose connections and shorts.
Label New Wiring and Circuits
Label all new wiring with source and destination. Label new breakers clearly. This avoids confusion later.
Install GFCIs and AFCIs
Protective GFCI and AFCI devices prevent shocks, fires, and save lives. Install them according to code.
Get Electrical Permits and Inspections
Electrical permits and inspections ensure work meets code and is safe. They also provide great advice.
Once you thoroughly plan the project and acquire the right gear, you're ready to start rewiring. Follow these steps:
1. Turn Off Electrical Power at Main Breaker
Shut off all power at the main breaker before starting. Verify it's off by testing with a voltage tester.
2. Remove Old Wiring
Carefully remove existing wiring. Pull it free from boxes and conduits, cut it out of drywall, unbundle it, and pull it out of the attic/crawlspace.
3. Drill Holes for New Wiring Runs
Drill holes through floor joists and wall studs to route new wiring between the main panel and device boxes. Follow your electrical plan.
4. Pull New Wiring Cables
Use fish tape to pull bundles of new NM cables through holes in framing. Leave plenty of extra length for connections.
5. Mount New Electrical Boxes
Mount plastic or metal boxes to framing where devices and fixtures will be located. Follow your electrical plan.
6. Make Wire Connections
Strip sheathing and connect hot, neutral, and ground wires securely inside each box and at the main panel.
7. Attach Devices to Boxes
Install receptacles, switches, lights, GFCIs, and other devices neatly into corresponding boxes.
8. Label New Wiring and Circuits
Carefully label new wiring and circuit breakers according to their locations/purposes. This avoids confusion.
9. Replace Walls, Fixtures, Faceplates
Patch drywall, replace insulation, install lights/fixtures, add faceplates, and repaint to hide rewiring work.
10. Turn Power Back On and Test
Turn the main breaker back on. Walk through the home testing outlets and lights to ensure all is working properly.
Follow these final tips for a successful project:
Work slowly and methodically. Rushing leads to mistakes.
Consult local codes and permit requirements. Get professional advice if needed.
Hire an electrician if you get stuck or overwhelmed. Safety comes first.
Invest in quality materials and tools. Don't cut corners to save money.
Carefully label everything. Taking photos helps too.
Check all connections for tightness before turning power back on.
Keep the area tidy and safe. Prevent tripping hazards.
Never work on "live" wires. De-energize circuits fully before handling wires.
By taking the proper time to plan and prepare, even beginners can safely rewire their home successfully. Just work methodically, follow safety procedures, and don't be afraid to get professional help when needed. Thoroughly renovating your home's electrical system yourself is a very rewarding do-it-yourself project that saves thousands in electrician fees.