How To Rewire Your 100 Year Old Home With Hidden Knob and Tube Wiring

Introduction

Rewiring a 100 year old home can be a daunting task, especially when dealing with outdated and potentially hazardous knob and tube wiring. As a homeowner, I have learned that with proper planning, safety precautions, and step-by-step execution, I can successfully rewire my vintage home. In this comprehensive guide, I will walk through all the key steps and considerations for replacing knob and tube wiring with modern, up-to-code electrical systems.

Dangers of Knob and Tube Wiring

Before beginning any rewiring project, it's crucial to understand the risks of outdated electrical systems like knob and tube. This early form of electrical wiring, common in homes built before 1950, has significant safety issues:

Fire hazard - Insulation breaks down over time, exposing live wires that can arc, spark, and ignite fires inside walls. Knob and tube has no protection like modern wire coverings.
Shock hazard - Outdated wiring lacks proper grounding, increasing risk of electric shock, especially when touching appliances.
Overloading - Designed for fewer electrical devices, knob and tube can be overloaded by modern energy usage needs. This leads to overheating.
Insurance issues - Many companies won't insure homes with knob and tube wiring due to fire risks.

I cannot stress enough that knob and tube wiring poses a serious danger in an old home. Replacing it should be a top priority project.

Pre-Rewire Inspection

Before developing a rewiring plan, I need to thoroughly inspect my home's existing electrical system. Here are key investigation steps:

Locate the main electrical panel - Note available slots for circuit breakers. Assess if an upgrade is needed.
Follow wiring routes - Track paths of knob and tube wires, noting insulation condition. Use an inspection camera inside walls if necessary.
Check outlets and fixtures - Assess connectivity of all lighting, receptacles, switches and appliances.
Document all wire gauge sizes. This determines required replacements.
Note all junction points connecting old and new wiring. These need reconnecting.
Label each circuit at the main panel and outlets.
Photograph the entire system for reference.

This inspection provides crucial information for developing my rewiring plan. I don't want any surprises once I start the removal process.

Developing a Rewiring Plan

With inspection complete, I can now strategize my rewiring approach:

New circuit map - Draw up new circuits with proper load balancing and number of outlets.
Upgrading electrical panel - Determine if higher amperage capacity needed for additional circuits.
Wiring material selection - Choose appropriate gauge and type of copper wiring. Romex is common.
Run wire through walls - Decide whether to fish wires through walls or if new openings are needed.
Outlet and switch placement - Meet code requirements for proximity, spacing and GFCI outlets.
Lighting needs - Ensure adequate lighting fixtures and switches per room.
Appliance connections - Kitchen and laundry circuits often need upgrades for larger loads.
Permit application - Check local permit requirements before starting.

Rewiring an old home takes foresight. A detailed plan minimizes delays and code violations once the work begins. I always have my plan inspected before pulling the first wire.

Removing Knob and Tube Wiring

With my new circuit plan approved, I can start the hazardous process of removing outdated wiring:

Turn off power - Shut off electricity at the main panel before any work. Test that power is off!
Remove devices - Detach any fixtures, outlets or switches from knob and tube wires.
Pull wires - Carefully pull individual wires out of outlets and junction boxes. Coils often accumulate inside walls.
Take down wire paths - Unscrew or cut knob and tube wires from structural studs and ceiling joists.
Inspect for hidden wires - Not all knob and tube is visible. Look for covered wires inside finished walls and ceilings before closing them up.
Dispose properly - Knob and tube wiring is typically coated in lead paint. Follow local hazardous waste disposal requirements.

Work slowly and methodically. Overlooking a single live wire could cause a major safety hazard once new wiring is installed. Be vigilant!

Installing New Wiring

With the old wiring removed, I can focus on installing modern replacement circuits:

Plan wire routing - Measure and mark exact wire paths for each circuit run. Follow code for wire gauge per circuit amperage.
Fish wires - Use glow rods and fish tape to carefully pull new wires through walls and ceilings between outlets and junction boxes.
Secure wires - Use insulated cable staples to attach wiring every 4.5-6 feet along support studs as required by code.
Connect circuits - Use wire nuts to connect circuit wires and grounding at all outlets, switches and junction points.
Mount devices - Securely fasten all new electrical boxes, outlets and switches in place.
Label - Mark each new circuit clearly at the breaker panel and all outlets. Important for troubleshooting!
Inspect - Have an electrician validate that all new wiring is properly sized, connected, grounded and secured before concealment.

Getting new wires in place is tedious but rewarding work. Go slowly to ensure safety and code compliance.

Hiring an Electrician

While a skilled DIYer can potentially rewire their own vintage home, I strongly advise hiring a licensed electrician, especially for:

Electrical panel - Upgrading or installing a new main service panel is best left to professionals.
Local codes - Navigating permit requirements, inspections and regulations can be challenging. Electricians ensure proper process is followed.
Certifications - Electricians carry liability insurance and know the latest NEC code requirements for installation.
Problem solving - Professionals have the experience to troubleshoot complex wiring situations and hazardous conditions.

Don't risk safety or code violations on your rewiring project. Hire a pro for items beyond your skill level.

Safety First!

Finally, I can't stress enough that safety is paramount when rewiring an old home. Potential hazards include:

Electric shock - Always power off circuits at the main breaker panel before wiring work. Verify wires are de-energized.
Electrocution - Be extremely careful not to contact live wires inside electrical boxes and conduit. This can kill!
Fire - Faulty wiring can overheat and ignite fires inside walls. Have an electrician inspect your work before turning circuits on.
Injury - Use care when working with sharp tools, wiring staples, and wire cutters. Ladders and crawl spaces also present risk.

Take your time and exercise extreme caution. The risk is not worth the reward when it comes to household electrical work. If in doubt, call an electrician.

Conclusion

Rewiring a 100 year old home with knob and tube wiring is a major project, but very worthwhile for safety. With proper planning, safety precautions, and help from a professional electrician, I can successfully rewire my old house. While challenging, I'll gain the peace of mind and added property value that modern electrical systems provide. Stay safe and be meticulous when reviving your vintage home!