I have an older home that still has original knob and tube wiring. This outdated electrical system can be hazardous and needs to be updated. Here is how I went about rewiring my home to remove the obsolete knob and tube wiring and install modern, safer electrical wiring.
Understanding Knob and Tube Wiring
Knob and tube wiring was commonly installed in homes built prior to the 1940s. This type of wiring consists of individual hot and neutral wires that are separated from each other. The hot wire is surrounded by ceramic knobs and the neutral wire by tubes, supported by porcelain insulators.
While knob and tube wiring was suitable for the electrical needs at the time, it does not meet modern electrical code requirements for a few reasons:
- Insulation - The hot and neutral wires are not insulated from each other. This creates a fire hazard.
- Grounding - Knob and tube systems do not have a ground wire. This can lead to electrical shocks.
- Capacity - Knob and tube wiring is not designed to handle the electricity load of modern appliances and devices.
So while I was still able to use my lighting and outlets, it was time to rewire my home to get rid of the obsolete, potentially dangerous knob and tube wiring.
Planning the Rewiring Project
Before starting the rewiring project, I needed to make sure I approached it carefully and systematically. Here are the steps I took in planning:
- Hire an electrician - Rewiring a home is complicated and dangerous. I hired a licensed, insured electrician to handle the project.
- Electrical load calculation - The electrician did a load calculation to determine how much electricity my home requires. This dictated the size of the new electrical panel and wires.
- Circuit mapping - The electrician mapped out all my existing circuits and determined new circuit layouts.
- Outlet and switch placement - We decided where to place new outlets and switches. I wanted to add more for convenience.
- Appliance and lighting plans - Based on my home appliances and lighting, the electrician made sure the new system could handle the load.
- Inspect attic and walls - The electrician inspected the attic and walls where new wiring would be run. Obstacles were identified before starting.
- Permits - The electrician obtained all the required permits for the rewiring project. This was important for following code.
Proper planning helped make sure the project went smoothly and the new electrical system met all safety requirements.
Removing the Old Knob and Tube Wiring
With planning complete, it was time to remove the antiquated, dangerous knob and tube wiring from my home. This involved carefully taking out all the old wiring components:
- I turned off the main electrical panel to de-energize the system. Safety first!
- The electrician removed the old electrical panel and wiring leading into and out of it.
- We accessed wiring through the attic, walls, and basement. Knob and tube wires were located and removed.
- I made sure the electrician removed all parts of the old system, including junction boxes, ceramic knobs, tubes, and insulators.
- Wires were pulled out carefully by hand to avoid unnecessary damage and drywall repairs.
- As old wiring was removed, the electrician made note of any insulation or air sealing that would need to be added back.
- Plaster and lath was removed from walls to fully access old wiring runs. The walls were built back up with drywall.
- All discarded knob and tube wiring was properly recycled or disposed of.
It was a lot of work, but after a few days my home was cleared of the old, dangerous obsolete wiring.
Installing New Wiring and Components
With the knob and tube wiring removed, the house was ready for the new, modern electrical system:
- The electrician installed a new 200 amp electrical service panel. This had plenty of room for circuit breakers.
- New wiring runs were installed through walls, attic, and basement per the circuit mapping.
- Grounded NM (nonmetallic) 12/2 wire was used for lighting and outlet circuits.
- 12/3 NM wire was used for major appliance circuits like kitchen, laundry, and AC.
- Copper wiring was used for safety and conductivity. Aluminum wiring can present fire risks.
- I opted for more outlets than required by code for convenience.
- GFCI outlets were installed in bathrooms, kitchen, garage, and exterior for protection.
- A-FCI outlets were used in other rooms for arc fault protection.
- Appropriate gauge wire was used for large load circuits to handle the electricity.
- New light switches were installed at planned locations.
- Walls and ceilings were patched up and repainted after new wiring installation.
The electrician also tidied up the wiring by:
- Properly splicing connections.
- Securing wires to joists and studs for support.
- Leaving proper excess wire lengths for adjustments.
- Labeling wires and circuits clearly in the panel.
Wrapping Up the Rewiring Project
To complete the rewiring project:
- The electrician performed insulation and air sealing where walls were opened up. This improved energy efficiency.
- Smoke and CO detectors were installed for safety.
- A whole house surge protector was added for electrical protection.
- Copper ground rods were driven outside to properly ground the system.
- Once everything was done, the electrician performed thorough testing on all circuits.
- With the system properly installed and tested, power was turned back on.
- The electrician helped me update my home insurance for the improved electrical system.
- All required inspections were passed by the local building department.
- I disposed of all old fixtures like lamp holders that were not compatible.
It wasn't a quick or easy process, but I now have safe, modern electrical wiring throughout my home after removing the obsolete, dangerous knob and tube system. It provides reliable power for my family's needs. I'm glad I made this important investment into my home's safety and comfort!