How to Rewire Your Home Without Professional Help

Rewiring your home can seem like a daunting task, but with proper planning and safety precautions, it is possible for a dedicated DIYer to complete. Here is a comprehensive guide on how to rewire your home without professional help.

Understanding Home Wiring Basics

Before beginning any electrical project, it is crucial to understand some fundamentals about home wiring and electricity. This knowledge will help ensure the project is completed safely and correctly.

Electrical Terminology

There are some basic terms related to home wiring that are helpful to know:

• Voltage - The force that drives electrical current, measured in volts. Most homes have 120-volt and 240-volt circuits.
• Current - The flow of electricity through a conductor, measured in amps. 15 amps is standard for lighting circuits.
• Wattage - The rate of electrical power, calculated by multiplying volts by amps.
• Circuit breaker - The safety device that automatically shuts off electricity to a circuit if it is overloaded.

Wiring and Cables

There are a few common types of electrical wiring and cables:

• Romex cable - The typical electrical wire for indoor wiring. It has insulation and bundled wires.
• NM-B cable - Romex cable rated for dry locations.
• UF-B cable - Romex cable rated for outdoor/underground use.
• Conduit - Pipe used to protect electrical wires. Can be metal or PVC.

Basics of Home Electrical Systems

• Most homes have a 120/240-volt electrical service provided by the utility company.
• The electrical panel distributes power to circuits in the home through circuit breakers or fuses.
• Lighting circuits are usually 15 amps. Outlets are normally 20 amp circuits. Large appliances like stoves or AC units require 240V circuits.

Planning Your Rewiring Project

Careful planning is mandatory before beginning a rewiring project. Rushing in without proper preparation can be unsafe. Follow these planning steps:

Evaluate the Existing System

• Inspect the electrical panel and all visible wiring. Look for any deficiencies or potential hazards.
• Use a voltage tester to check all outlets and light fixtures. Make note of any that are not getting power.
• Figure out exactly what parts of the home need rewiring. This could be certain rooms, or replacing old knob-and-tube wiring.

Choose a Rewiring Method

There are a few approaches to rewiring a home:

• Full rewire - Replacing all wiring in the home. Very labor intensive.
• Partial rewire - Only replacing wiring in some rooms or sections that need upgrades. More common for DIY projects.
• Running new circuits - Adding new wiring for additional circuits without replacing existing wiring.

Decide which approach best suits your needs.

Develop a Wiring Diagram

• Draft up a wiring diagram mapping out your new circuit layout.
• Indicate all the outlets, lights, switches and major appliances on each circuit.
• Plan where your new wiring runs will be located and how you will feed them from the panel.

Calculate Electrical Load

• Add up the wattage ratings for all lights and outlets on each new circuit.
• Remember most household circuits can safely support 1800-2000 watts.
• Separate high wattage appliances like stoves onto their own 240V circuits.

Purchase Materials and Tools

Make sure to have all required materials and tools on hand before starting:

• Romex cable or other wiring
• Conduit and fittings (if using)
• Outlet and switch boxes
• Circuit breakers
• Wire strippers, cable cutters, hand tools
• Voltage tester, multimeter
• Ladders and work lights

Consider Getting Electrical Permits

• Most areas require permits and inspections for home rewiring. Research your local requirements.
• Permits help ensure the work meets electrical codes. Inspections can catch any defects.

Safely Rewiring and Replacing Circuits

Once planning is complete, it’s time to safely rewire. Take it slow and be cautious when working with electrical wiring.

Turn Off Power and Working Safely

• Turn off all power at the main breaker before starting any electrical work. Verify it is off with a voltage tester.
• Never touch wires or work on live circuits. Electrocution is possible.
• Use a multimeter to double check wires are dead before touching them.
• Keep the work area dry and clear of flammable materials.

Running New Circuit Wiring

• Choose routes between the panel and outlets/lights that minimize wire length and holes in walls. Run wires through attic, basement or crawlspace if possible.
• Calculate required wire gauge and breaker size based on circuit amperage and voltage. Follow codes.
• Use conduit for exposed wiring runs. Secure cables at least every 4.5 feet.
• Drill holes carefully through studs. Use grommets to protect cables from sharp edges.
• Label all wires with origin and destination for identification.

Installing Outlets, Switches and Lights

• Confirm all boxes are correct size and type for their purpose. Avoid overcrowding wires in boxes.
• Make wire connections securely using approved methods like wire nuts or screw terminals.
• Attach cables firmly to boxes with cable clamps.
• Use correct wire gauge for switches and outlets based on connected load.
• Attach cover plates and test operation of all installed devices before securing them.

Connecting Circuits at the Panel

• Shut off the main breaker again before working inside the panel. Double check for live wires.
• Match the correct gauge breaker to each new circuit based on amperage. Follow manufacturer specs.
• Connect hot wires securely to breakers, neutral wires to neutral bus bar, grounds to ground bus bar.
• Follow proper conventions like having 240V breakers in top rows only.
• Ensure at least 1 inch of space between wires entering/exiting panel.

Testing and Turning Power Back On

• With all wiring complete, turn the main breaker on momentarily to test all circuits.
• Flip each breaker off and back on individually. Walk through the home testing outlets, lights and switches on each.
• If any circuits trip immediately, inspect wiring again for shorts. Use a multimeter to troubleshoot.
• Once all circuits test safely, leave main breaker on and enjoy the improved wiring!

Following Safety and Electrical Codes

Compliance with all applicable electrical codes and best safety practices is crucial during any home rewiring project.

Key Safety Practices

• De-energize circuits - Turn off power before starting and verify it is off.
• Personal protective equipment - Wear insulated gloves and eye protection.
• Tools/materials - Use only properly insulated tools rated for electrical work. Choose code-compliant wiring and parts.
• Avoid water - Never work in wet conditions or allow wiring to contact water.

National Electrical Code (NEC) Compliance

The NEC outlines legal requirements for safe electrical installations:

• Overcurrent protection - Circuit breaker/fuse amperage matches wire size.
• Load calculations - Ensure circuits are not overloaded by connected devices.
• Wiring methods - Use approved cabling and connections like NM cable, conduit, etc.
• Outlets spacing - Follow mandated spacing between outlets on a circuit.
• GFCI protection - Install ground fault circuit interrupters near water sources.

Permits and Inspections

• Electrical permits are required in most areas for rewiring projects.
• An initial electrical inspection will check wiring access.
• A final inspection is done to confirm code compliance before concealment.

Proper planning, safe working practices and compliance with electrical code requirements will help ensure your DIY home rewiring project is a success. Pay close attention to details and don't hesitate to consult an electrician if any issues come up. Take your time and prioritize safety.