Knob and Tube Wiring Insurance Problems in Wisconsin

Knob and Tube Wiring: The Insurance Headache for Wisconsin Homeowners

If you own an older home in Racine, Kenosha, Milwaukee, or anywhere in southeastern Wisconsin, there is a reasonable chance it was built with knob and tube wiring. This early electrical wiring method was standard from the 1880s through the 1940s, and it can still be found in tens of thousands of Wisconsin homes — running through attics, walls, and basements.

Knob and tube wiring is not illegal in Wisconsin. It is not automatically dangerous. But it is increasingly becoming an insurance problem that can cost you your coverage, complicate a home sale, or force an expensive rewiring project on a tight timeline.

What Is Knob and Tube Wiring?

Knob and tube (K&T) wiring uses individual conductors — a hot wire and a neutral wire — run separately through the house, supported by ceramic knobs (where wires change direction) and ceramic tubes (where wires pass through framing). There is no ground wire and no cable jacket.

When installed correctly and left undisturbed, knob and tube wiring can function safely for decades. The problems start when:

Insulation is added over K&T wiring. This is the biggest issue. Knob and tube wiring was designed to dissipate heat into the open air. When blown-in insulation or batts are packed around it (common during energy efficiency upgrades), the wires overheat. This is a genuine fire hazard.
The wiring has been modified improperly. Over 80 to 100 years, previous owners, handymen, and sometimes even licensed electricians have spliced into K&T circuits in ways that are unsafe — using improper connections, overloading circuits, and creating hazardous junctions hidden in walls.
The rubber insulation has deteriorated. The cloth-and-rubber insulation on K&T wiring becomes brittle over time, cracking and exposing bare copper. This is especially common in hot attics and near heat sources.
The system is being asked to do more than it was designed for. A K&T system was designed for a handful of light bulbs and a radio. Modern homes draw far more power, and overloaded K&T circuits are a fire risk.

The Insurance Problem

Here is where it gets urgent for Wisconsin homeowners. Insurance companies have been steadily tightening their policies on knob and tube wiring:

Some insurers will not write a new policy on a home with active knob and tube wiring. If you are buying a home with K&T, you may struggle to get coverage — and without insurance, your mortgage lender will not close the loan.
Some insurers require an inspection of the K&T wiring by a licensed electrician before they will issue or renew a policy. The electrician must certify that the wiring is in safe condition and not covered by insulation.
Some insurers charge significantly higher premiums for homes with active K&T, adding $500 to $1,500+ per year to your costs.
Some insurers will non-renew your policy if they discover K&T wiring during a claim investigation — meaning you had coverage, but lost it when you needed it most.

The specific policies vary by carrier, and the Wisconsin market has been shifting toward stricter requirements over the past several years. If you are shopping for insurance or renewing a policy on a home built before 1950, ask your agent specifically about their knob and tube policy.

The Inspection Process

When an insurance company requests a K&T inspection, here is what happens:

A licensed electrician inspects all accessible K&T wiring — typically in the attic, basement, and any open walls.
The electrician looks for deteriorated insulation, improper modifications, contact with building insulation, overloaded circuits, and other hazards.
The electrician provides a written report certifying the condition of the wiring.
The insurance company reviews the report and decides whether to issue, renew, or modify the policy.

An inspection typically costs $150 to $350 and takes one to two hours. It is money well spent even if your insurer has not asked for one — knowing the condition of your wiring is valuable information.

Replacement Options and Costs

If your K&T wiring needs to be replaced, there are several approaches:

Full Rewire

Replacing all knob and tube wiring with modern Romex (NM) cable is the gold standard. This involves running new wiring through the walls, installing new outlets and switches, and connecting everything to a modern panel. For a typical 1,200 to 2,000 square foot Wisconsin home, a full rewire costs $8,000 to $20,000, depending on the number of circuits, accessibility of the walls, and whether you are opening walls or fishing wire through existing cavities.

Partial Rewire

In some cases, it makes sense to rewire the circuits that are in the worst condition or that are covered by insulation, while leaving undamaged, accessible K&T in place. This can reduce costs to $3,000 to $10,000 but does not fully eliminate K&T from the home.

Circuit Abandonment

Sometimes individual K&T circuits can be abandoned (disconnected at the panel) and replaced with new circuits. This is a targeted approach that addresses specific problem areas.

Wisconsin-Specific Considerations

Several factors make knob and tube wiring particularly relevant in Wisconsin:

Energy efficiency programs: Wisconsin's Focus on Energy program and various utility rebates encourage homeowners to add insulation. If your home has K&T in the attic, you cannot safely add insulation until the K&T is removed or replaced. Insulation contractors in SE Wisconsin are trained to look for K&T before blowing insulation, but it is not always caught.
Older housing stock: Racine, Kenosha, Milwaukee, and many surrounding communities have large numbers of homes built in the 1900s through 1940s. K&T is extremely common in these neighborhoods.
Home sale complications: Wisconsin real estate transactions frequently involve K&T as a negotiation point. Buyers' inspectors flag it, insurance requirements create urgency, and sellers may need to address wiring to close the deal.

Frequently Asked Questions

Is knob and tube wiring legal in Wisconsin?

Yes, existing knob and tube wiring is legal in Wisconsin. You are not required by law to remove it. However, you cannot install new K&T wiring (it does not meet current code), and you cannot cover existing K&T with insulation. The practical issue is not legality — it is insurance availability and safety.

Can I get insurance with knob and tube wiring?

Yes, but your options may be limited. Some major carriers will insure homes with K&T after a satisfactory inspection by a licensed electrician. Others will not. If your preferred carrier declines coverage, an independent insurance agent can often find a policy through a surplus lines carrier, though the premium will be higher. Addressing the K&T wiring — even partially — opens up more insurance options and better rates.

How do I know if my home has knob and tube wiring?

Check your attic and basement for signs: white ceramic knobs screwed to framing, ceramic tubes passing through joists, and individual cloth-covered wires (rather than modern plastic-jacketed cable). If you see two-prong outlets without a ground, that is another indicator but not definitive — some homes were rewired with two-wire Romex that also lacks a ground. A licensed electrician can perform a thorough assessment.

Concerned about knob and tube wiring in your home? Call Couillard Electric at (262) 618-2851 for a free estimate. We inspect, assess, and replace K&T wiring for homeowners throughout Racine, Kenosha, and southeastern Wisconsin.