Introduction
I want to talk about the process of replacing knob and tube wiring in your home. Knob and tube wiring was commonly installed in homes built before the 1940s. It features exposed wires running through ceramic knobs and tubes. While it was suitable at the time, knob and tube wiring is now outdated and potentially dangerous. Replacing it can significantly reduce fire risks and allow you to use modern appliances. In this article, I'll go through everything you need to know to successfully replace knob and tube wiring.
Dangers of Knob and Tube Wiring
Before we get into the replacement process, it's important to understand why knob and tube wiring needs to be replaced in the first place. Here are some key reasons:
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Fire hazard - The insulation on old knob and tube wiring becomes brittle and cracks over time, exposing the wires. This can lead to sparks and electrical fires. Knob and tube lacks modern safety features like grounding.
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Overloading - Knob and tube wiring was not designed to handle the electricity demands of modern appliances like air conditioners, large TVs, and computers. This can overload the system and cause fires.
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No grounding - Proper grounding protects you from electrocution and shocks. Knob and tube systems have no grounding wire.
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Insurance issues - Many insurance companies will not insure homes with knob and tube wiring, or charge a higher premium. Replacing it may lower your rates.
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Resale value - Knob and tube wiring can make buyers hesitant and reduce your home's value. Updating the wiring improves resale value.
Replacing knob and tube wiring provides huge safety and financial benefits, so let's look at the process.
Planning the Replacement Project
Replacing your home's electrical wiring is a big project that requires careful planning:
Hiring an Electrician
I strongly recommend hiring a licensed and experienced electrician to replace knob and tube wiring. The project involves dealing with live electrical lines, which can be extremely hazardous. Leave it to the professionals. Make sure to get multiple quotes and check reviews before choosing an electrician.
Getting Necessary Permits
Check with your local building department to see what permits are required. The electrician will usually obtain the proper permits, but it's good to be aware of them. Common permits include electrical, plumbing, and structural.
Determining Scope of Work
The electrician will examine your home's wiring and determine the full scope of work required. Key factors include:
- How much knob and tube wiring needs replacement
- Whether the home's electrical panel needs upgraded
- If new wiring routes are required
Knowing the full scope of work allows proper budgeting. Be prepared for a potentially big project.
Budgeting
Costs for replacing knob and tube wiring vary greatly based on your home's specifics, but $8,000 to $15,000 is typical. Get multiple quotes to compare pricing. Also factor in costs for repairing walls, plumbing, etc after the old wiring is removed. Budget adequately and consider financing options if needed.
Timing the Project
Plan the project during cooler weather when you can safely go without air conditioning for a few days. Also avoid major holidays. Give yourself extra time in case of delays or unexpected issues.
Replacing the Wiring
Once the project is planned out, it's time to replace the outdated wiring:
Removing Knob and Tube Wiring
The electrician will:
- Shut off power
- Remove old wiring from outlets, switches and light fixtures
- Take down ceramic knobs and tubes
- Pull wires out of walls
Removing all the old wiring can take several days for a whole home.
Running New Wiring
Modern electrical wire comes in plastic or rubber sheathed cables. The electrician will:
- Drill holes to route new wires between floors and through framing
- Run cables from the electrical panel through walls and ceilings to each outlet and switch
- Connect switches, lights, receptacles, and appliances using pigtails
Proper circuit labeling at the panel makes the system organized and safe.
Installing Grounding
A key upgrade is installing grounding wires. The electrician will:
- Run grounding wire from pipes, metal frames, outlets etc back to the main panel
- Connect the neutral and grounding bars in the panel
- Install GFCI outlets for protection from shocks
Proper grounding means the whole system is now up to modern safety standards.
Inspecting and Testing
Once the new wiring is installed, the electrician will:
- Visually inspect all connections
- Perform continuity tests on wiring runs
- Check grounding and polarity
- Verify proper operation of outlets, switches and fixtures
- Make any final adjustments
Thorough inspection and testing ensures long-term safety and reliability.
Finishing Up the Job
The last steps include:
Wall Repair
Holes drilled for wiring will need patched up with plaster and paint. The electrician can handle this or you can hire a general contractor. Proper patching keeps your home looking good as new.
Panel Upgrade
If needed, upgrade your home's main electrical panel to support added circuits. A 200 amp panel is typical for modern homes.
Final Inspection
The local building department will perform a final inspection before giving approval. This ensures all work was completed to code.
Cleanup
Finally, clean up any dust or debris from the wiring replacement. Check that furniture is put back properly. Install plates and covers over outlets. Your home should now be safe with modern wiring!
Replacing knob and tube wiring is a major undertaking, but worthwhile for safety and peace of mind. Follow this process and work closely with electricians and inspectors to get the job done right. You'll gain significant safety benefits and improve your beautiful home.