How to Replace Knob and Tube Wiring in a 100 Year Old Home

Assessing the Knob and Tube Wiring

As the owner of a century home built in the 1920s, I have quite a bit of original knob and tube wiring that needs replacing. This antiquated wiring system was common in homes built before the 1930s but poses major fire and safety risks today. Before beginning the replacement process, I need to thoroughly assess the extent of the knob and tube wiring throughout my home.

Here are the steps I took to evaluate my existing wiring:

• I inspected the basement, attic, and all accessible walls/ceilings for the distinctive knob and tube wiring. This wiring has ceramic knobs that act as insulators and cloth-covered wiring running between them.
• I looked for junction boxes and spliced connections, making note of all locations.
• I hired a qualified electrician to do a more thorough inspection. They checked wiring conditions in walls and hard-to-reach areas.
• The electrician performed a load calculation test to ensure my electrical service could handle the additional demand of modern wiring and appliances.

Once I had a complete understanding of the knob and tube wiring situation, I was able to move forward with replacing it.

Developing a Replacement Plan

Replacing knob and tube wiring in an old home is a major project that requires careful planning. As I developed my replacement plan, here are some key factors I considered:

• Scope of work - I decided to replace all of the old wiring, not just sections. This ensured a completely modernized and safer electrical system.
• Routing - New wiring often needs to follow a different route than the old. I planned each run carefully, thinking about access points and obstruction removal.
• Electrical panel - My 100 year old fuse panel needed upgrading to a modern circuit breaker panel to handle added circuits.
• Permits - I researched permit requirements and scheduled inspections with my local building department. They required seeing all new wiring before covering it.
• Protection - I planned to keep lights and critical circuits powered throughout the project. This involved using temporary wiring and generators.
• Budget - I got quotes from 3 electricians and compared costs for materials and labor. Total costs ranged from $8,000-$12,000.

Creating a well-conceived plan was crucial for executing this complex project smoothly. It also ensured I wasn't stuck dealing with surprises mid-project.

Removing the Old Knob and Tube Wiring

With my replacement plan in place, I was ready to start ripping out the old wiring. This had to be done with care to avoid damaging my home. Here is how I removed the knob and tube wiring:

• I turned off power at the main fuse box to de-energize all wiring.
• The electrician double checked all circuits with a non-contact voltage tester. Safety first!
• We accessed wiring through unfinished spaces like the attic and basement whenever possible. This required less demolition.
• For finished walls and ceilings, I carefully cut access holes to expose wiring that needed removal.
• We disconnected each run from the fuse panel and any spliced connections.
• I extracted wiring from the knobs and tubes or pulled it out of conduits. Removing knobs required some force.
• All openings were covered temporarily to protect my home while rewiring work continued.

By methodically dismantling the old system, I was able to remove all the antiquated and potentially hazardous knob and tube wiring.

Running New Wiring Circuits

With the knob and tube wiring out of the way, the rewiring phase could begin. Running new wires involved:

• Planning circuits - The electrician mapped out all the required circuits, confirming they matched my panel capacity.
• Pulling wires - We used existing access points when possible, but also cut new holes to route wires through framing.
• Making connections - The electrician properly spliced wires into junction boxes and connected them to outlets and switches.
• Securing wires - Cables were stapled neatly along framing using insulated staples to avoid damage.
• Labeling - All circuit wires were labeled at endpoints and the electrical panel. This makes circuits easy to identify.

Safety was also top of mind during rewiring:

• We used the appropriate gauge wire for each circuit's amperage needs.
• All junction boxes and access holes were sealed to contain fire spread.
• I chose copper wiring rather than aluminum for maximum safety and conductivity.
• The electrician ensured proper grounding for outlets, switches, and appliances.

The new wiring provides the safe, robust electrical capacity my old home needs.

Upgrading the Electrical Service Panel

A crucial part of my rewiring project was upgrading from an antiquated fuse box to a modern circuit breaker panel. This involved:

• Selecting a large capacity panel to support added circuits down the road.
• The electrician disconnecting wires from the old panel and removing it.
• Mounting the new panel per code requirements and manufacturer specifications.
• Reconnecting all the wires to the appropriate new circuit breakers.
• Grounding the panel properly with a conductor wire to an exterior grounding rod.

The new panel's circuit breakers provide overcurrent protection that far surpasses my old screw-in fuses. And there is room for expansion capabilities.

Restoring Surfaces

With the knob and tube wiring replaced, I still had some restoration work to do:

• Patching holes - I closed up all walls and ceilings using drywall, plaster, or wood patches as appropriate.
• Painting - Patched areas were sanded smooth and repainted to match the original surface.
• Insulating - I blew in new insulation in attics and walls for better energy efficiency.
• Testing - The electrician performed insulation resistance testing to confirm no wires were damaged during installation.

Restoring surfaces took time but was satisfying to see my home looking fresh and improved. The restoration process also allowed me to inspect the finished wiring job.

Lessons From My Knob and Tube Wiring Replacement Project

After completing this major electrical upgrade project, I gained some worthwhile experience and knowledge:

• Replacing old wiring is extremely labor-intensive, so hiring electricians is often wise.
• Allow extra time in your schedule, especially if unexpected issues arise mid-project.
• Protecting furnishings from dust and debris takes effort - use tarps and seal access holes.
• Coordination is key - make sure all contractors and inspectors stay aligned on schedule.
• Document before pictures - photos of old wiring proved useful for assessing needs and progress.

While certainly no easy task, replacing the knob and tube wiring has made my house safer and more livable. The sense of accomplishment is tremendous!