How to Remove Knob and Tube Wiring

Knob and tube wiring was commonly installed in homes built before 1940. This old electrical wiring is outdated and potentially dangerous, so many homeowners look to remove it. Here is a comprehensive guide on how to fully remove knob and tube wiring from your home.

Dangers of Knob and Tube Wiring

Knob and tube wiring consists of individual wires that are run through the framing cavities in walls and ceilings. They are supported by ceramic knobs and tubes. There are several concerns with this old wiring method:

• Fire hazard - The wiring is not grounded and lacks insulation, which can lead to overheating and electrical fires. The fire risk is greatly increased.

• Shock hazard - Exposed wires increase the chances of shocks and electrocution. This presents a serious safety issue.

• Inadequate for modern loads - Knob and tube wiring is not designed to handle the electricity demands of modern appliances and devices. This can lead to dangerous overloading.

• Insurance issues - Many insurance companies will not insure a home with knob and tube wiring due to the substantial risks. This can make your home uninsurable.

• Resale value - Homebuyers are often hesitant to purchase homes with knob and tube wiring. This can severely impact your home's resale value.

For these important reasons, it is highly recommended that knob and tube wiring be completely removed and replaced.

Preparing for Knob and Tube Removal

Removing knob and tube wiring is a major project that requires extensive preparation:

• Have an electrician inspect - A licensed electrician should inspect your knob and tube wiring to assess the full scope of the job.

• Check local permit requirements - Most areas require permits for rewiring projects. Be sure to check your local regulations.

• Plan for power outages - Rewiring will require turning off power as you work. Plan for extended outages.

• Determine if rewiring is DIY or pro - Rewiring is complex. Unless you have electrical expertise, hire a licensed electrician.

• Decide if you'll replace all wiring - For safety, it is best to rewire the entire home rather than just replace the knob and tube.

• Develop a detailed budget - Rewiring an entire home is very expensive. Get multiple estimates and factor in all costs.

• Clean before starting - Remove all items from walls, attics, and crawlspaces where you'll be working. This allows for easier access.

Proper planning and preparation will help your knob and tube removal project go smoothly.

Removing Knob and Tube Wiring

The actual process of removing knob and tube wiring involves several key steps:

1. Turn Off Electrical Power

Start by turning off power at the main electrical panel. This prevents dangerous shocks. Then disconnect any individual circuits as needed.

2. Remove Fixtures, Outlets, and Switches

Remove light fixtures, outlets, switches, and any other components wired with the old knob and tube. This allows access for removal.

3. Locate all Wiring

Find where knob and tube wires are running. Look in attics, crawlspaces, and inside walls. Remove attic insulation if needed to expose wiring.

4. Cut Wires

Once wiring is exposed, carefully cut the individual wires to remove from fixtures, supports, and distribution points. Cut wires as close to the supports as possible.

5. Remove Knobs, Tubes, and Other Supports

With wiring removed, take out any remaining ceramic knobs, porcelain tubes, or other supports. Be sure to remove all old wiring components.

6. Pull Wires Out

After cutting wires and removing supports, pull the individual wires out from the walls, ceilings, and other cavities. Use care to avoid leaving any wires behind.

7. Patch and Repair Surfaces

With old wiring removed, patch and repair any holes or damage to walls, ceilings, and other surfaces. This returns spaces to their original condition.

8. Dispose of Old Wiring Properly

Finally, dispose of the removed knob and tube wiring safely. Copper and other metals can often be recycled.

By methodically following these steps, you can completely remove hazardous and outdated knob and tube wiring.

Replacing Knob and Tube Wiring

Once knob and tube wiring is removed, it needs to be replaced with modern wiring:

• Use NM (nonmetallic) cable - NM cable has insulated wires bundled in a plastic sheath. It meets current safety codes.

• Run new circuits - Reconfigure wiring with enough circuits for all your home's electrical needs.

• Install grounding - Modern wiring must have a grounding system, unlike knob and tube.

• Update electrical panel - A new panel may be needed to handle added circuits. Consult an electrician.

• Install GFCIs - GFCI (ground fault circuit interrupter) outlets provide protection from shocks. Use for outlets near water sources.

• Meet all codes - Have an electrician ensure new wiring meets all electrical and building codes. This guarantees safety.

The overall rewiring project can take weeks in an average home. Hire professional electricians unless you have specialized skills. It is not a DIY project for most homeowners.

Cost to Remove and Replace Knob and Tube

Factor in these average costs when budgeting to remove knob and tube wiring:

• Knob and tube removal - $2,000 to $4,000

• Complete home rewiring - $8,000 to $15,000

• New electrical panel - $1,000 to $3,000

• Permits - $100 to $500

• Professional electrician fees - $50 to $100 per hour

In total, removing knob and tube and rewiring a whole home often costs $10,000 to $25,000. Get multiple estimates to compare costs for your specific project.

Removing hazardous and outdated knob and tube wiring is a major but important project for homeowners. Following this comprehensive guide will help you successfully remove knob and tube and rewire your home safely. Consult electricians to ensure the work meets all codes and standards. The substantial investment will pay off in safety and peace of mind.