How to Safely Replace Knob and Tube Wiring in Your Home
Replacing knob and tube wiring in your home can seem like a daunting task, but with proper planning and by following safety precautions, it can be done safely. Knob and tube wiring was commonly installed in homes built before 1950 and has largely been phased out due to safety concerns. While not inherently dangerous, knob and tube wiring lacks modern safety features like grounding and can be a fire hazard if damaged or overloaded. By taking the right steps, you can upgrade to modern wiring and enjoy peace of mind knowing your home's electrical system is safe and up-to-date.
Reasons to Replace Knob and Tube Wiring
There are several compelling reasons to replace knob and tube wiring:
No grounding - Knob and tube lacks a grounding wire which is essential for preventing shocks and allowing faults to trip breakers. This makes it less safe than modern wiring.
Insulation deterioration - The insulation on old knob and tube wiring becomes brittle and cracks over time, creating a fire hazard.
Overloading circuits - Antiquated wiring often can't handle the electricity demands of modern appliances and devices. This can lead to overheated wires and fire risks.
Faulty connections - Loose, corroded connections in old wiring can cause intermittent faults making lighting flicker and reducing reliability.
Limited circuits - Most knob and tube wiring has very few circuits resulting in not enough outlets in each room for modern needs.
Deters buyers - Most buyers are hesitant to purchase a home with outdated knob and tube wiring due to safety concerns and upgrade costs.
May violate insurance - Many insurance companies won't insure a home with knob and tube or charge higher premiums, making it harder to sell.
Dangers of DIY Knob and Tube Wiring Replacement
While it's tempting to replace knob and tube wiring yourself to save money, there are risks:
Shocks and electrocution - Mistakes working around live electricity can result in serious injury or death by electrocution.
Fire hazards - Faulty materials or improper installation can lead to electrical fires which are dangerous and destructive.
Insurance issues - DIY electrical work may violate your insurance policy if not up to code. Any resulting damage may not be covered.
Decreased property value - Incorrect or incomplete wiring replacement can actually deter buyers and decrease your home's value.
For these reasons, it is strongly recommended to hire a licensed electrician rather than attempting DIY replacement of knob and tube wiring.
Hiring an Electrician
When hiring an electrician, be sure to:
Verify licensing and insurance - Electricians should be licensed by your state and carry liability insurance in case of property damage or injuries.
Check references - Reputable electricians can provide references from past wiring replacement jobs to vouch for their expertise.
Get multiple quotes - Interview at least 3 electricians and compare their quotes, experience, and referrals.
Agree on a contract - Get a written contract outlining timing, materials, warranties, permits, and final costs to avoid misunderstandings.
Request certified inspection - Once work is complete, get an inspection by your local building department to ensure it is properly done and up to code.
Step-by-Step Process for Replacement
A typical knob and tube replacement project involves the following steps:
- Hire a licensed, insured electrician
- Agree on a contract detailing scope of work and timeline
- Obtain proper permits from building department
- Have electrician walk through to plan the rewiring
- Electrician installs new electrical panel if needed
- Electrician disconnects and removes old knob and tube wiring
- Any rodent damage or insulation cracking identified and remedied
- Structural repairs done where walls/ceilings were cut for wiring access
New Wiring Installation
- Electrician runs new wiring through walls and ceilings
- All wiring terminated in outlets, switches, and appliances
- GFCIs, AFCIs, and other modern safety devices installed
- All new wiring, boxes, and devices properly grounded
Testing and Completion
- Electrician performs safety tests on all new circuits and wiring
- Walls patched, painted, and restored from installation work
- Request final inspection from building department
- Make final payment to electrician upon passing inspection
Costs of Replacement
Depending on your home's size and existing wiring, costs typically range:
- Materials - $1000 to $3000 for all new wire, outlets, switches, breaker panel, etc.
- Labor - $3000 to $8000 for an experienced, insured electrician's installation time
- Permits - $100 to $500 depending on your municipality
While not cheap, this significant upgrade is a smart investment improving your home's safety, functionality, and resale value for decades to come.
- Replacing obsolete knob and tube wiring improves safety and functionality
- Dangers of DIY electrical work means hiring a professional is strongly advised
- An experienced, licensed electrician will follow codes to ensure safe installation
- Typical costs range from $5000 to $12,000 depending on home size and scope
- The peace of mind and increased home value are worth the investment into modern wiring
With proper planning and hiring a pro, you can successfully upgrade outdated wiring for a safer, more reliable electrical system. Contact reputable electricians in your area for quotes on knob and tube replacement costs and your options.