How to Rewire Your Home Without an Electrician and Stop Getting Shocked

Introduction

Rewiring a home can seem like a daunting task, but with proper planning and safety precautions, it's possible for a handy homeowner to rewire their house without hiring an electrician. I've done it in my own home, and while challenging, it allowed me to upgrade the electrical system and add new circuits at a fraction of the cost of hiring an electrician.

In this guide, I'll walk through the complete process of rewiring a home, from assessing the existing electrical system, to choosing the right wire gauges and circuit breakers, to running new wires and installing outlets and switches. I'll also cover key safety tips to avoid getting shocked or causing a fire hazard. Follow along to gain the confidence to rewire your home!

Assessing Your Existing Electrical System

The first step is to understand the current state of your electrical system. Here's what to look for:

Take Note of All Fixtures and Outlets

• Walk through the entire house room by room and take notes on all existing electrical fixtures and outlets. Note which rooms lack sufficient outlets and where you may want to add new lighting fixtures. This will help plan the circuits for the rewired home.

Identify the Main Service Panel

• Locate the main service panel, which will have the main breaker that shuts off power to the whole home. This is where the incoming electrical service from the utility company connects to your home's circuits.

• Open the main panel and note the amp rating of the main breaker. This will determine the total capacity of your home's electrical system.

• Also note the number of circuit breaker slots and spaces available in the panel. This will determine how many circuits you can add when rewiring.

Check the Wire Gauge and Age

• In the main panel, inspect the wire gauge of the existing wiring. Older homes often have smaller 14 or 12 gauge wire which may need to be upgraded to allow for increased electrical load.

• Check the age and condition of the wiring. Brittle or cracked wire insulation can present fire and shock hazards. Rewiring is recommended if the home wiring is over 40 years old.

Look For Knob and Tube Wiring

• Inspect the attic and basement for older knob and tube wiring, which was phased out in the 1930s. This outdated wiring is unsafe and must be completely removed and replaced when rewiring.

Planning Your New Circuits

Once you've assessed the existing system, it's time to map out the new circuits for the rewired home.

Consult Electrical Code

• Check the National Electrical Code (NEC) requirements based on your home's location and size. The NEC dictates how many circuits are required and for which rooms.

• For example, kitchen and bathrooms require dedicated 20 amp circuits. Follow all applicable codes when planning new circuits.

Calculate Total Amp Needs

• Add up the amp rating of all fixtures and appliances on each proposed circuit. The total amps on a standard 15 amp residential circuit should not exceed 80% of 15 amps, which is 12 amps.

Draw a Circuit Map

• Map out new circuits on paper, labeling each proposed circuit and listing which outlets/fixtures it will serve. Plan for adequate circuits in each room based on use, and include circuits for any new additions like a home office.

Include Essential Circuits

• Ensure your plans include these essential circuits:

• • Lighting circuits for each section of the home
• • Individual 20 amp circuits for kitchen outlets
• • Individual 20 amp circuits for bathrooms
• • Washer/dryer circuit
• • Furnace circuit
• • AC unit circuit

Consider Arc-Fault Protection

• The NEC now requires arc-fault circuit interrupter (AFCI) protection on most home circuits to prevent fire from damaged wiring. Consider adding combination AFCI breakers in the main panel to comply with code and improve safety.

Selecting the Right Wire Gauge

Choosing the appropriate wire gauge for your home's circuits is critical for safety and performance. Follow these tips:

Follow Code Minimums

• The NEC provides minimum acceptable wire gauge for 15 and 20 amp circuits:

• • 15 amp circuits - Use #14 AWG copper wire
• • 20 amp circuits - Use #12 AWG copper wire

• Only use thicker, higher capacity wire, never thinner than code minimums.

Consider Voltage Drop

• When current passes through wire, some voltage is lost. Using thicker wire reduces this voltage drop.

• For runs over 75 feet from panel to outlet, use #12 AWG for 15 amp circuits to allow a 3% or less voltage drop.

Match Breaker to Wire Size

• The circuit breaker amp rating must match the ampacity of the wire size used.

• Never pair a 15 amp breaker with #12 wire or a 20 amp breaker with #14 wire. This can overload the wire and cause a fire.

Choosing the Right Circuit Breakers

Selecting properly rated circuit breakers is equally important for a safe rewiring project.

15 vs 20 Amp Breakers

• Use 15 amp breakers for general lighting and outlet circuits. This supports up to 15 amps and 1800 watts.

• Use 20 amp breakers for major appliances like refrigerators, disposals and laundry rooms which have higher amp draw.

Use GFCI Breakers Where Needed

• Install GFCI breakers to protect wet areas like bathrooms, kitchens, laundry and outdoor outlets from shocks.

Use AFCI Breakers to Prevent Fires

• Install combination AFCI breakers to meet code and provide arc fault protection. This prevents fires from damaged wiring.

Get High Quality Breakers

• Purchase new circuit breakers from reputable brands like Square D or Eaton. Avoid no-name breakers that may fail to trip when overloaded.

Running New Wiring Through Walls

Now comes the tough part - running the new wires through the walls. Here are some tips:

Map Out Runs Beforehand

• Carefully plot the circuit runs on your floor plan, marking all outlet and switch locations. Measure wire runs and cut wires ahead of time.

Fish Wire Through Walls

• Use a fish tape to feed new wires down walls and across ceilings. Keep the wire runs as short and straight as possible.

• Have a helper feed the fish tape from the other end to make fishing easier for long runs.

Drill Holes to Route Wires

• Drill small holes through wall studs and joists to route wires between rooms. Avoid drilling near pipes, ducts or chimneys. Patch holes later with drywall compound.

Staple Wires Properly

• Use insulated staples every 2-3 feet to secure wire runs. Keep staples loose enough to allow wires to slide. Overstapling can damage wire insulation.

Label Wires Clearly

• Use colored tape near endpoints and write circuit numbers on wire insulation with a permanent marker for easy identification.

Installing New Outlets and Switches

The fun part is finally installing the new outlets, switches and other fixtures:

Use Old Boxes If Possible

• When possible, use the existing electrical boxes for new outlets and switches. This avoids extra drywall patching.

• If adding boxes, install old work brackets securely between studs.

Install GFCIs Where Needed

• Install GFCI outlets in wet/damp locations like kitchens, bathrooms and outdoors. Press the "Test" then "Reset" buttons to ensure proper function.

Choose Durable Products

• Buy commercial or spec grade outlets - avoid cheap residential models. Look for backwire holes to secure wires.

• Opt for smooth durable switches rated for heavy use. Large paddles are great for hallways.

Connect Wires Securely

• Loop wires clockwise around screws to prevent loosening from vibration. Tug test each wire to ensure tight connection.

• Cap all unused wires with twist-on wire connectors. Neatly tuck back into electrical box.

Linking Breakers and Circuits

With the wires run and outlets installed, it's time to make connections.

Shut Off Main Breaker First

• Before wiring the panel, shut off the main breaker! Verify power is off using a non-contact voltage tester. Work safely!

Match Wire Size to Breaker

• Use #14 AWG for 15 amp breaker circuits and #12 AWG for 20 amp circuits. Overheating can occur if breaker amps exceed wire capacity.

Connect Neutrals and Grounds

• Inside the panel, connect all neutral/white wires to the neutral bus bar. Connect all ground/bare copper wires to the ground bar.

• Ensure a proper grounding electrode system using ground rods or water pipes.

Label Circuits Clearly

• Label each circuit clearly on the panel door. This makes shutting off circuits for maintenance easy.

Consider Arc-Fault Breakers

• For added fire protection, connect AFCI circuit breakers at the start of each circuit run. These will trip on damaged wiring before a fire starts.

Testing and Safety Checks

With the new wiring complete, it's critical to test all circuits thoroughly and ensure safety before turning the system live.

Check for Loose Wires

• Tug test every wire connection to ensure tight and secure connections. Loose wires can overheat or short.

Verify Ground Connections

• Use a multimeter to check for proper grounding at each outlet. This protects from shocks.

Test GFCI Circuits

• Press the "Test" button on each GFCI outlet to verify protection from shocks. Re-test regularly.

Inspect for Damage

• Check that wire insulation has not been pinched or pierced anywhere. Damaged insulation can lead to shorts and fires.

Turn On Power Gradually

• When ready, switch the main breaker on, then carefully switch on each circuit one at a time while checking for problems.

Conclusion

Rewiring a home is a major project, but also very rewarding. By taking proper precautions, using quality materials, adhering to electrical codes, and thoroughly testing my work, I was able to completely upgrade the electrical system in my home and gain peace of mind knowing it is safer and more robust. This allows me to take on larger electrical projects with confidence. I hope this overview gives you a great starting point to tackle your own home rewiring project! Let me know if you have any other questions.