how knob and tube wiring brings collapse, shock, and disaster waiting to strike

Tue, 05 May 2026 16:34:17 +0000

Knob and Tube Wiring: A Silent Threat in Older Homes That Can Lead to Collapse, Shock, and Disaster In homes built before the mid-20th century, the hidden infrastructure beneath the walls holds stories few homeowners realize are still present—and dangerous. One of the most overlooked hazards is knob and tube (K&T) wiring, an early electrical system that, while once standard, now poses serious risks of electrical fires, shocks, and even structural collapse. ### What Is Knob and Tube Wiring? Knob and tube wiring was widely used in the U.S. from the 1890s through the 1950s. Unlike modern Romex cable, K&T consists of insulated copper conductors run in airproof ceramic knobs connected by porcelain tubes—no walls or floors penetration. While the insulation sometimes lasts decades, the system lacks grounding and is not designed for today’s electrical loads, making it a ticking time bomb.