Knob and Tube Wiring: Dangers and Replacement Options

Oregon has thousands of homes built before 1950 that may still contain knob and tube (K&T) wiring. While this wiring method was standard for its era, it presents significant safety concerns by today's standards. If your older Oregon home has knob and tube wiring, understanding the risks and replacement options is essential for your family's safety.

What Is Knob and Tube Wiring?

Knob and tube wiring uses ceramic knobs to support wires along structural members and ceramic tubes to protect wires where they pass through joists and studs. The wires are insulated with a rubber cloth coating and run individually -- one hot wire and one neutral wire -- rather than bundled together in a cable like modern Romex wiring. K&T wiring has no ground wire, which is a fundamental safety limitation.

Fire Risks

The primary danger of knob and tube wiring is fire. The rubber and cloth insulation deteriorates over decades, cracking and exposing bare copper wire. When exposed wires contact wood framing, insulation, or other combustible materials, the result can be a fire. Additionally, K&T wiring was designed for the electrical loads of the 1920s through 1940s -- far less than what modern homes demand. Overloading K&T circuits generates heat that the aging insulation cannot safely handle.

The Insulation Problem

Knob and tube wiring was designed to dissipate heat into the open air around it. When blown-in insulation is installed in walls and attics -- a common energy efficiency upgrade -- it buries K&T wires and traps heat around them. This dramatically increases fire risk. Oregon building code prohibits installing insulation in contact with knob and tube wiring, meaning you cannot properly insulate your home until the K&T wiring is replaced.

Insurance Issues

Many insurance companies in Oregon either refuse to insure homes with active knob and tube wiring or charge significantly higher premiums. Some will provide coverage only after an electrical inspection confirms the K&T wiring is in good condition and not overloaded. If you are buying or selling an older Oregon home, K&T wiring will likely be flagged during the inspection and may complicate the transaction.

Replacement Options

The safest approach is a complete knob and tube wiring replacement, which involves running new grounded Romex cable throughout the home. This is typically done in conjunction with a panel upgrade to handle modern electrical loads. In some cases, a partial replacement may be possible, targeting the most critical areas first while planning for full replacement over time.

The Replacement Process

A full home rewiring typically takes 5-10 days depending on the size of the home and accessibility of the wiring paths. The process involves running new wiring through walls, installing new outlets with ground connections, upgrading the panel, and removing or abandoning the old K&T wiring. Some drywall work may be needed, though experienced electricians minimize wall openings.

Take Action

If your Oregon home has knob and tube wiring, do not wait for a problem to develop. Call (877) 883-2383 for a professional assessment. Our licensed electricians specialize in K&T replacement and can provide a clear plan for upgrading your home's wiring safely and efficiently, improving both safety and insurability.