How to Safely Replace Knob and Tube Wiring in Your Old House

Introduction

Replacing knob and tube wiring in an old house can seem like a daunting task, but with proper planning and safety precautions, it can be done safely by a homeowner. Knob and tube wiring was commonly installed in homes built before 1950 and lacks the insulation and safety features of modern electrical wiring. Over time, the insulation deteriorates, wires fray, and connections come loose, posing fire and electrocution hazards. Updating the wiring improves safety and allows you to enjoy the convenience of grounded outlets and modern electrical capacity. This guide will walk you through the key steps to safely replace knob and tube wiring yourself.

Dangers of Knob and Tube Wiring

Before deciding to rewire, it's important to understand the risks of keeping the outdated knob and tube wiring:

• Fire hazard - Frayed wire insulation can allow wires to arc to combustible materials in walls and attics. This electrical arcing can ignite fires.

• Shock hazard - Exposed conductors from deteriorated insulation can energize metal boxes and surfaces, posing a serious shock risk.

• Insufficient capacity - Knob and tube wiring lacks grounding and is only designed to handle up to 60 amps total for the house. This prevents running multiple modern appliances.

• Insurance issues - Many insurance companies won't issue policies for homes with knob and tube wiring due to the substantial risks.

Replacing the old wiring eliminates these serious hazards.

Planning the Rewiring Project

Careful planning is crucial when taking on a large project like rewiring a home. Follow these planning steps:

Consult an Electrician

• Hire a licensed electrician to evaluate your existing wiring and provide a rewiring plan. They can identify any specialist skills, materials, or tools needed so you can determine if DIY is feasible.

Research and Education

• Read DIY guides to understand fundamental electrical concepts and safety procedures. Watch wiring tutorial videos to prepare.

Create a Wiring Diagram

• Work with your electrician to create a detailed wiring diagram showing the layout of new switches, outlets, lights, and connections. This serves as an essential reference during the project.

Obtain Necessary Permits

• Apply for electrical and building permits from your local building department. Permits ensure your work meets local codes and allow for certified inspections.

Purchase Materials and Tools

• Buy all required wiring, boxes, switches, outlets, breakers, and conduit ahead of time per the wiring plan. Also obtain all recommended safety gear and electrical tools.

Safety Tips for Rewiring

Replacing old wiring comes with inherent hazards. Follow these tips to ensure safety:

Turn Off Power at Main Breaker

• Switch the main breaker to off before starting any work. Verify power is off by testing outlets with a multimeter or voltage tester.

Work on Non-Energized Wires Only

• Do not work on any live wires. Always double-check wires using a non-contact voltage detector before touching.

Wear Protective Gear

• Use rubber-soled shoes, gloves, long sleeves and eye protection when handling wires. Never work on wiring wearing metal jewelry which can conduct electricity.

One Circuit at a Time

• Rewire only one circuit at a time to avoid confusion. Label each wire clearly as it is disconnected.

Use GFCIs and Avoid Overloads

• Install GFCI outlets as required by code. Use properly rated wires, boxes, switches and breakers to prevent overloads.

Step-by-Step Rewiring Process

With proper planning and safety steps completed, you're ready to replace the old knob and tube wiring. Follow this general process:

1. Turn Off Power and Inspect Existing Wiring

• Shut off the main breaker then inspect how existing wiring is run to each location. Look for any asbestos insulation. Take photos for reference.

2. Remove Old Wiring

• Work one circuit at a time. Remove outlet and switch cover plates then disconnect and remove wires. If necessary, cut into walls and ceilings to remove wires.

3. Install New Wiring and Boxes

• Run new cables along planned routes. Staple cables to studs or joists every 4.5 ft. Install new electrical boxes at each location.

4. Connect Switches, Outlets and Lights

• Follow wiring diagrams to connect new circuits. Securely fasten each wire to terminals. Verify ground connections.

5. Install New Breakers

• Connect new circuit wires to appropriately sized breakers in the service panel. Ensure polarity is correct.

6. Have Work Inspected

• Call the building department to inspect wiring and authorize the service panel before turning power on.

7. Turn Power Back On and Test

• Turn the main breaker on. Use a voltage tester to verify power at outlets. Test appliances on each circuit.

Consider Hiring an Electrician

While a DIY rewiring project can save money over hiring an electrician, it isn't for everyone. If you lack electrical skills or feel uncomfortable working with wiring, consider hiring a licensed electrician to guarantee safe and proper rewiring. They can also handle tricky tasks like replacing service panels. Get multiple quotes to find reasonable rates.

Replacing hazardous knob and tube wiring improves home safety and functionality but requires diligent planning and precaution when tackling as a DIY project. Follow the guidance in this article to ensure you safely upgrade the wiring in your vintage home. Stay tuned for more DIY wiring tips and guides!