Knob-and-Tube Wiring: Why It’s a Problem and How to Replace It [2026]

If you own a home built before the 1940s in Metro Atlanta or anywhere in Georgia, there is a good chance your walls still contain knob-and-tube wiring. While this system was considered perfectly safe when it was installed, it was never designed to handle the electrical demands of modern life. Knob and tube wiring replacement is one of the most important upgrades you can make to an older home, both for safety and for practical reasons that affect your insurance, your resale value, and your family’s well-being.

In this post, we will break down exactly what knob-and-tube wiring is, why it creates real problems for Georgia homeowners in 2026, how to tell if your home still has it, and what the replacement process actually looks like.

What Is Knob-and-Tube Wiring?

Knob-and-tube (K&T) wiring was the standard method of residential electrical wiring in the United States from the late 1880s through the early 1940s. The system uses porcelain knobs to support individual hot and neutral wires run through open air along joists and studs. Where wires pass through framing members, porcelain tubes protect them from contact with the wood.

Unlike modern wiring, K&T has no ground wire. The hot and neutral conductors are run separately rather than bundled inside a protective sheathing. The insulation is typically a rubberized cloth that degrades over decades of exposure to heat and moisture.

In its original form, with no modifications and in good condition, knob-and-tube wiring is not inherently dangerous. The problem is that very few K&T systems in 2026 are still in their original form or in good condition.

The Risks of Keeping Knob-and-Tube Wiring

Fire Safety Concerns

The most serious risk is fire. Over 80 or more years, the rubber and cloth insulation on K&T wires becomes brittle and cracks, exposing bare copper conductors. When those bare wires contact wood framing, insulation materials, or each other, the result can be arcing, overheating, or an electrical fire.

The danger increases dramatically when blown-in insulation has been added to walls or attics. K&T wiring was designed to dissipate heat into open air. When insulation surrounds these wires, heat builds up with no way to escape, and the risk of ignition goes up significantly.

Amateur modifications make things worse. Many older K&T systems have been spliced into with modern Romex wire using improper connections, often without junction boxes. These hidden splice points are a common source of electrical fires in older Georgia homes.

Insurance Difficulties

Many insurance companies in Georgia will not write a new homeowner’s policy on a house with active knob-and-tube wiring, or they will charge substantially higher premiums. Some carriers require a full electrical inspection before binding a policy on any pre-1950 home. If K&T is found to be active, they may require knob and tube wiring replacement before providing coverage.

This is not a minor inconvenience. It can delay or even kill a home sale if the buyer cannot secure insurance.

Inadequate Electrical Capacity

A typical K&T system was designed for a 30- or 60-amp service, powering a handful of light fixtures and maybe a radio. Today’s homes demand 200-amp service to run HVAC systems, kitchen appliances, computers, EV chargers, and more. Overloading K&T circuits with power strips and adapters is extremely common and extremely dangerous.

The lack of a ground wire also means that three-prong outlets installed on K&T circuits are not actually grounded, even if they appear to be. This leaves your electronics and your family unprotected from ground faults.

How to Tell If Your Home Has Knob-and-Tube Wiring

If your home was built before 1945 in the Atlanta metro area, you should assume K&T wiring may be present until proven otherwise. Here are some signs to look for:

• Porcelain knobs or tubes visible in the attic, basement, or crawl space, often along joists or rafters
• Two-prong outlets throughout the home, which indicate the absence of a grounding system
• Round, push-button light switches or other vintage-style fixtures
• Cloth-covered wiring visible at any exposed point, sometimes with a dark, crumbling appearance
• A fuse box rather than a modern breaker panel

Even if you spot some of these indicators, a licensed electrician should perform a thorough inspection to determine how much K&T wiring is still active versus abandoned in place. Some homes have a mix of old and new wiring, which can actually be more dangerous than a fully original system due to improper splicing.

How Knob-and-Tube Wiring Replacement Works

Full knob and tube wiring replacement is a significant project, but it is well worth the investment. Here is what the process generally involves:

1. Inspection and assessment. A licensed electrician evaluates the entire electrical system, maps out all active K&T circuits, and identifies any hazardous modifications.
2. Planning and permitting. In most Georgia jurisdictions, a full rewire requires an electrical permit and must be performed to the current National Electrical Code (NEC) standards.
3. Running new wiring. New grounded circuits using modern NM-B (Romex) cable are run throughout the home, replacing every active K&T circuit. This wiring and rewiring work often involves accessing wall cavities, attic spaces, and crawl spaces.
4. Panel upgrade. In most cases, the electrical panel is upgraded to 200-amp service to support modern demand.
5. Inspection and closeout. The local jurisdiction inspects the completed work before it is finalized.

The goal is to de-energize and isolate all K&T wiring so it is no longer carrying current. In many cases, the old wires are left in place inside walls because removing them would require tearing open every wall cavity, but they are fully disconnected and abandoned.

A full rewire typically takes several days depending on the size and complexity of the home. A skilled electrician can often complete the work with minimal drywall disruption by fishing wires through existing cavities.

Frequently Asked Questions

Is knob-and-tube wiring illegal in Georgia?

Existing K&T wiring is not illegal. You are not required by law to remove it simply because it is old. However, it cannot be extended or used in any new construction, and it must meet current code standards during any renovation that involves the electrical system. Many homeowners pursue replacement proactively due to insurance requirements and safety concerns.

Can I get homeowner’s insurance with knob-and-tube wiring?

Some carriers will insure homes with active K&T, but options are limited and premiums are typically higher. Many of the major insurers in Georgia require knob and tube wiring replacement before issuing a standard policy. An inspection report from a licensed electrician documenting the condition of the wiring can sometimes help, but full replacement is the most reliable path to affordable coverage.

How long does a full rewire take?

For a typical older Atlanta-area home, a complete rewire generally takes three to five days of on-site work, though scheduling inspections and any necessary drywall repair can extend the total timeline. Larger homes or those with complex layouts may take longer.

Can I do a partial replacement and just replace the worst sections?

Partial replacement is possible and sometimes makes sense as a short-term measure, but it is not ideal. Mixing old K&T with modern wiring creates junction points that must be properly handled, and it does not solve the underlying capacity and grounding issues. Most electricians and insurance companies recommend a full replacement for the best long-term outcome.

If your Metro Atlanta home was built before the 1940s and you are unsure about the condition of your wiring, the team at Kalahari Electrical Services is here to help. As a family-owned Georgia electrician since 2001, with a 4.9 Google rating and A+ BBB accreditation, we stand behind every job with a 100% satisfaction guarantee. Give us a call at 678-665-2309 to schedule an assessment and find out exactly what your home needs.