Rewiring a home can be a daunting task, but with proper planning and safety precautions, it is possible to do it yourself without electrician certification. Here is a comprehensive guide on how to rewire your home safely and legally without an electrician license.
Understanding Electrical Wiring Basics
Before beginning any electrical project, it is crucial to understand some basic electrical concepts and components of home wiring:
- Voltage - The force that pushes electrical current, measured in volts. Most homes have 120V and 240V circuits.
- Current - The flow of electricity through a conductor, measured in amps. Standard 15A and 20A circuits.
- Circuits - Closed paths that electrons follow from the power source through conductors and back. Homes have multiple circuits powering lights, outlets, and appliances.
- Conductors - Wires that carry current, typically copper. Insulated wires prevent shocks and fires.
- Overcurrent protection - Fuses and circuit breakers that interrupt power if too much current flows through a circuit. Prevents fires and damage.
- Outlets and switches - Devices that connect appliances to circuits and control light/power. Follow proper wiring diagrams.
- Grounding - Paths for excess currents to safely reach the ground. Use copper ground wires and connections.
Having a solid grasp of these basics is the foundation for safely rewiring a home DIY. Consider taking an electrical theory course at a local community college if unfamiliar.
Gather the Right Rewiring Supplies
Before starting, acquire the necessary supplies for the rewiring project:
- Electrical wire - Use the correct wire gauge for the intended circuit capacity. Most common are 14 AWG and 12 AWG.
- Wire strippers - A must for removing insulation from wires. Self-adjusting strippers make things easier.
- Voltage tester - Essential for safely checking if circuits are live before working on them. Both contact and non-contact testers are handy.
- Cable ripper - Makes pulling old wires out of walls much simpler.
- Fish tape - Flexible steel tape for routing new wires through cavities and walls.
- Cable staples - Secures wires to studs and joists per electrical code. Staple at regular intervals.
- Wire nuts - Twists wires together securely inside junction boxes and at fixtures. Get the right size for the wire gauge.
- Electrical tape - Insulates wire connections and splices. Self-fusing silicone tape works well.
- Junction boxes - Houses connections and splices. Use correct size and type for each location.
- Conduit and fittings - Metal or PVC tubing that protects wires. Use when wiring without existing cables.
Having all the necessary supplies ready makes the rewiring go smoothly and safely. Check local regulations for any additional requirements.
Turn Off Power and Inspect Existing Wiring
The first step is to turn off power to the circuits that will be rewired at the main electrical panel:
- Set the main breaker to "off" to kill power to the entire panel.
- Then turn off the individual circuit breakers that connect to the rooms and fixtures being rewired.
- With a non-contact voltage tester, check wires to confirm power is off.
- Remove cover plates, fixtures, and outlets to access wires. Inspect condition of existing wiring.
- Check for cracked/frayed insulation, overheated wires, loose connections, etc. This informs rewiring needs.
- Take pictures of existing wiring for reference as you rewire.
- Plan new wire routes and connections based on existing setup and your desired changes.
Ensuring power is off and thoroughly inspecting old wiring is crucial for safety.
Remove Old Electrical Wiring
With power confirmed off, start removing old wiring:
- Unhook wires from outlets, switches and fixtures. Disconnect them at junction boxes too.
- Use a cable ripper to pull wires out of walls. Be careful not to damage drywall.
- Pull wires out of conduit gently to avoid breaking them. Conduit may be reused.
- Completely remove abandoned wires back to the panel. They can be a fire hazard if left in walls.
- Dispose of old wiring properly. Copper can be recycled for scrap value.
- Inspect interior of wall boxes and conduit. Clean out debris before rewiring.
- Mark wall openings where new wires will be routed. Cut new openings as needed with a drywall saw.
Taking out all the old wiring allows a fresh start for the new home wiring.
Run New Wiring Through Walls and Conduit
Now new wiring can be routed throughout the home:
- Start by running a ground wire from outlet boxes back to the main panel ground bus bar. Use #12 copper wire.
- Use a fish tape to thread wires through walls. Keep at least 12 inches of extra wire at boxes.
- For new circuits, run cable between panel and first outlet. Then connect outlets in a daisy chain.
- Use cable staples every 4-6 feet and at least 1 inch from stud edges. Keep wires secure and damage-free.
- Run wires through conduit between finished spaces. Install proper fittings at junction box connections.
- Avoid kinks and over-tensioning wire when pulling through conduit. Use lubricant to minimize friction.
- Keep wire runs as short and direct as possible, especially for 240V circuits. Avoid unnecessary splices.
- Use junction boxes to house splices and connections. Size boxes based on number of conductors.
- Label wires at both ends for easy identification using tags or tape.
Take it slow and steady to properly route new wires through the entire home.
Install New Outlets, Switches and Fixtures
The final step is installing devices, outlets and fixtures with the new wiring:
- Strip insulation from wire ends using proper strippers for the wire size. Avoid nicking copper.
- Make tight electrical connections by twisting wires together with wire nuts or crimp connectors.
- Ground all devices properly using ground wires and ground screws. This ensures safety.
- Install junction boxes where multiple wires are spliced. Keep splices accessible.
- Attach outlets and switches to boxes securely using mounting screws. Follow manufacturer directions.
- Insulate all connections and splices with electrical tape. This prevents shorts and shocks.
- Install new light fixtures, exhaust fans, etc according to instructions. Make wire splices inside j-boxes.
- Use blank cover plates to cover unused junction box openings. Prevents unintended contact with live wires.
- Affix wire and junction box covers properly before restoring power.
Double check all connections are tight, insulated and grounded before completing rewire.
Restore Power and Test Circuits
The final step is powering up the newly wired home:
- Turn the main breaker back on at the panel. Check for proper voltage at the panel bus bars before proceeding.
- Switch on the individual circuit breakers one at a time.
- Go to each outlet, switch and fixture to ensure proper operation.
- Test with a voltage tester to confirm power at outlets. Check grounded and ungrounded outlets separately.
- Verify each connected light and appliance functions properly when the corresponding switch is turned on.
- Go around the entire home testing each outlet and switch. Catch any missed connections.
- Check for hot spots at junction boxes that may indicate loose wires or improper splices.
- If any issues are found, turn off the circuit and check connections. Rewire as needed.
- Examine rooms for grounded surfaces or fixtures that now spark - indicates faulty grounding.
Thoroughly testing each circuit protects your home and makes sure all new wiring works correctly.
Proceeding slowly with safety as the priority means a DIY rewiring project can upgrade your home's electrical system successfully. Pay close attention to all details of the electrical code and be prepared to get help from a professional electrician if any complex wiring challenges arise. With diligence and care, it is possible for many homeowners to rewire their house without certification. Just be sure to have the city inspect the work when complete to ensure it meets code.