Why Replace Knob and Tube Wiring


From the 1880s to the 1930s, knob and tube wiring was the standard electrical wiring system used in most North American buildings. Designed as an open-air system, the single-insulated copper conductors ran through walls or ceilings and were supported by ceramic knob insulators, which served to separate wires from combustible framing.

Today, however, knob and tube wiring is woefully outdated. And for good reason.

The Dangerous Problems Associated With Outdated Knob and Tube Wiring

When it comes to knob and tube wiring, there are several big problems homeowners need to understand.

For starters, homes with knob and tube wiring may not have the electrical capacity to meet today’s needs. This can lead to frustration—and much more: big appliances will fail more frequently, circuits will blow more often, and an overload in the wiring may even lead to electrical fire.

There are also financial consequences of sticking with knob and tube wiring. When it comes to selling or renovating your home, the law prohibits knob and tube wiring to remain in place if any outlets or circuits are added. With that in mind, insurance companies are increasingly canceling or refusing home insurance policies until old circuits and wiring are replaced.

But most importantly, knob and tube wiring can be downright dangerous. Old, fragile wires are a major fire hazard, because they can too easily be damaged by rodents or simple oversights. Moreover, knob and tube wiring wasn’t installed with a grounding conductor—which is now legally required by today’s safety standards. That means if anything goes awry with the current, the electricity has no recourse and can cause fatal electric shock.

Fortunately, there have been plenty of important updates in the way we handle circuits and wiring—and we are adept in them all.