Rewiring a home is a complex project that requires knowledge of electrical systems, safety protocols, and building codes. While hiring a licensed electrician is highly recommended for major rewiring jobs, some minor updates can potentially be DIYed by a knowledgeable homeowner. This guide will walk through the key steps, considerations, and requirements for rewiring a home without professional help.
Understanding Electrical Basics
Before attempting any electrical work, it's crucial to understand some fundamental concepts about how home electrical systems function. This includes:
- Current - The flow of electrons through a conductor. Measured in amps.
- Voltage - The electrical potential difference that causes current to flow. Measured in volts.
- Wattage - The rate at which electricity is consumed. Calculated by multiplying amps x volts.
- Circuits - The closed path through which current flows from the main panel to outlets/lights and back.
- Overcurrent protection - Fuses or circuit breakers that shut off power to prevent hazards if too much current flows.
In addition, it's vital to understand basic wiring and connection methods. Key principles include:
- Hot vs neutral wires - The hot wire carries power while the neutral returns it to the panel.
- Ground wires - Provide a safe path for stray current to prevent shocks. Must connect to metal boxes/fixtures.
- Wire nuts - Twist-on connectors used to join wires together.
- GFCI outlets - Shut off power if an abnormal current is detected to prevent shocks. Often required in kitchens, baths, etc.
Grasping these fundamentals is essential for safely rewiring any part of your home.
Gathering the Right Tools and Materials
Rewiring a home requires having the proper tools and materials on hand. Essential items include:
- Voltage tester - To safely check for live wires.
- Wire strippers - For removing insulation from wire ends.
- Cable ripper - To remove old cables from walls.
- Fish tape - For pulling new wires through walls.
- Wire nuts & connectors - For joining wires and cables.
- Voltage tester - To safely check for live wires.
- Cable staples - To secure new wiring to framing.
- Wire - New copper wiring of appropriate gauge for the circuit size.
- Electrical tape - For insulating wire connections.
- Wall plates & receptacles - New outlets and cover plates.
- GFCI outlets - For replacement of non-GFCI outlets in wet areas.
- Junction boxes - For housing wire connections.
Purchasing supplies from electrical retailers ensures components are up to electrical code standards.
Shutting Off Power and Working Safely
Safety is paramount when rewiring a home. Proper precautions include:
- Use a non-contact voltage tester to confirm power is off before starting work.
- Shut off the main breaker and all individual circuit breakers involved in the rewiring.
- With power off, remove old fuse panel fuses if applicable.
- Turn off the power main switch next to the meter outside.
- Keep a fire extinguisher handy in case of electrical mishaps.
- Wear electrical gloves and avoid jewelry when handling wires.
Working on dea-energized circuits drastically reduces the risk of shocks or electrocution.
Removing Old Wiring
The first hands-on step is dismantling existing wiring. It's best to:
- Use a cable ripper to remove wiring from walls. Don't just pull wires out.
- Carefully extract wires from electrical boxes and fixtures.
- Label wires as they are disconnected to note their location.
- Cap all wires using wire nuts to avoid exposed copper.
- Coil up disconnected wires and secure them temporarily out of the way.
- Dispose of old wiring properly rather than just tossing in the trash.
Taking time to remove old cables neatly will make installing new wiring easier.
Routing and Pulling New Wiring
Next comes the challenging task of routing new wires:
- Plan the wiring paths - try to follow existing routes where possible.
- Carefully drill holes through wall studs for routing wire between rooms.
- Use fish tape to pull cables through walls and ceilings between outlets.
- Ensure wires have slack and aren't pulled taut. Tight wires risk damage over time.
- Use cable staples to neatly secure wiring to framing along the route.
- Avoid running wires parallel too close to water pipes or across sharp edges.
- Junction boxes are required anytime wires are spliced together.
Take it slow when pulling new wires to avoid damaging insulation and creating hazards.
Splicing and Terminating New Wiring
After running cables, they must be properly connected:
- Carefully strip insulation from wire ends using proper strippers. Avoid nicking copper.
- For outlets, connect the hot (black) wire to the brass screw, neutral (white) to silver screw, and ground (green/bare) to the green screw.
- Twist matching wires together securely using wire nuts or crimp connectors.
- Wrap connections with electrical tape for additional insulation.
- Attach wires to fixtures and devices using manufacturer specified methods.
- Ensure wires have slack in boxes rather than pulling taut.
- Use plastic cable clamps to secure cables entering metal boxes.
All connections must be secure and adequately insulated to prevent hazards.
Testing and Turning Power Back On
Once the new wiring is installed, it's time to activate it:
- Carefully examine all wiring connections and fix any issues. Loose wires can cause arcing.
- Replace all removed fuses or reset breakers. Fuse amperage must match circuit capacity.
- Verify all wall switches function properly. Add/remove switch leg wires if needed.
- With the main still off, do an initial power-on test of outlets using a tester.
- Turn the main power back on. Recheck all outlets to confirm proper voltage and polarity.
- Verify all grounded devices show continuous ground on a tester. This ensures proper safety.
- Push the test button on all GFCI outlets to confirm they trip and cut power as expected.
- Check that all connected lights and appliances operate correctly.
Meticulously testing all wiring helps catch any lingering connection issues.
Following Electrical Codes
It's critical that all rewiring work meets National Electrical Code standards. Key requirements include:
- Using the proper wire gauges for circuit amperage - typically 12 or 14 AWG for 15/20 amp household circuits.
- Ensuring load calculations do not exceed breaker ratings.
- Having GFCI protection for all kitchen counter, bathroom, laundry, and outdoor outlet circuits.
- Maintaining required clearance around panels and junction boxes.
- Not overfilling electrical boxes which risks damaging wires.
- Having an accessible disconnect for hardwired equipment like HVAC units.
- Passing all inspection requirements for your municipality.
Cutting corners on codes could create serious safety issues and risks failing inspection.
Rewiring a home yourself can save money but requires diligence. If tackling major rewiring, consult an electrician to avoid potentially hazardous mistakes. But minor jobs like replacing switches and outlets can certainly be DIYed successfully with proper knowledge. Just always make safety the top priority.