If a home inspector or insurer mentioned knob and tube wiring, you’re not alone. Many older Seattle and Greater Seattle homes still have sections of this early electrical system. Knob and tube replacement is one of the most common insurance- and sale-driven electrical projects we complete for residential clients.
Need an assessment? Schedule a free estimate · Call 360-668-9540.
What Is Knob-and-Tube Wiring?
Knob-and-tube (K&T) uses ceramic knobs and tubes to support individual hot and neutral conductors through joists and walls. It was standard long before modern grounded Romex-style cable.
Problems today include:
- No equipment grounding conductor on many circuits
- Insulation that becomes brittle with age
- Circuits modified or buried under insulation in ways that trap heat
- Limited capacity for modern kitchen, bath, office, and EV loads
- Insurance carriers that refuse coverage or raise premiums until replaced
Do You Have to Replace All of It?
Not always on day one—but leaving active K&T long term is rarely the best plan in a modern Seattle home.
Common approaches:
| Approach | When it fits |
|---|---|
| Full replacement | Widespread K&T, sale/insurance deadline, whole-home remodel |
| Phased replacement | Budget staging; prioritize kitchens, baths, bedrooms, and high-load areas |
| Isolate + abandon | Safe de-energizing of old runs while new circuits take the load |
A licensed electrician maps what’s live, what’s abandoned, and what still feeds lights and receptacles.
Seattle Insurance, Inspection, and Sale Reality
- Buyers and lenders often require K&T remediation before closing
- Insurers may demand replacement timelines
- City permits and inspections apply to rewiring work
If you only need a letter for underwriting, ask for a documented assessment—then a clear replacement proposal.
How Knob-and-Tube Replacement Works
- Site survey — identify remaining K&T, panels, and grounding
- Scope — whole-home vs priority rooms; panel capacity needs
- Permit — pull electrical permit with the local AHJ
- Install — new grounded circuits, boxes, devices, and labeling
- Inspection — pass final before close-out
- Finish coordination — drywall/paint often by owner or GC
Many projects pair K&T removal with a panel upgrade and modern AFCI/GFCI protection.
Cost Factors (Planning Level)
Knob-and-tube replacement cost tracks the same drivers as house rewiring cost in Seattle:
- How much K&T is still active
- Wall/ceiling access and finish quality
- Whether the service panel needs upsizing
- Number of new circuits and devices
- Permit and inspection requirements
Avoid the cheapest “no permit” offers—failed inspections and insurance claims make them expensive later.
Cities We Serve for K&T and Rewiring
Farmers Electric regularly handles knob-and-tube replacement and residential rewiring in:
Seattle · Bellevue · Redmond · Kirkland · Bothell · Woodinville · Kenmore · Shoreline · Lake Forest Park · Edmonds · Lynnwood · Everett · Renton · Snohomish and surrounding service areas.
Safety Tips Until Replacement Day
- Don’t overload suspect circuits with space heaters or high-draw tools
- Never bury active K&T under heavy insulation without professional guidance
- Investigate burning smells or warm outlets immediately (emergency electrician)
- Use GFCI protection where code requires on new or replacement work
Schedule Knob-and-Tube Replacement
From a pre-sale punch list to a full home rewire, our EL01 licensed team will document what’s there and replace it the right way.
Schedule free estimate · 360-668-9540 · Wiring services · Residential electrical LP
Related: House rewiring cost Seattle · Does your home need rewiring? · Residential electrician Greater Seattle