Retire the Wiring Behind Your Walls

Why knob and tube is a problem now, not in 1930

The system was installed correctly for the load of its era: a few lights and a radio. The conductors were rubber insulated with a cloth braid, run in open air where heat could dissipate, and spliced with solder. Ninety years later the rubber has hardened and cracked, particularly near light fixtures and in attics that hit 140 degrees every Tri-Cities summer. Once insulation crumbles at a termination, bare conductor sits inside a box or against a joist.

The second issue is what got added later. Knob and tube circuits routinely have modern branches spliced into them, feeding rooms and appliances they were never sized for. There is no equipment ground anywhere in the system, so a fault in an appliance has no designed path back to the panel. Blown in insulation added during a weatherization retrofit compounds it by trapping heat around conductors that were meant to sit in open air.

Where it turns up in the Tri-Cities

Knob and tube is mostly found in homes built before roughly 1945, which in this area means older neighborhoods in Kennewick and Pasco, farmhouses around Prosser and Benton City, and scattered pre war houses elsewhere. Richland is a different story. Most of the Hanford era housing built from 1943 through the early 1950s was wired with early cable rather than knob and tube, but that early cable often has no equipment ground and cloth insulation that is aging the same way.

That distinction matters when you are quoting a job. A Richland alphabet house may not need knob and tube removal and still need rewiring for the same underlying reason. Kyle inspects the attic, the crawlspace, the panel, and a sample of device boxes before saying which system you actually have. Guessing from the year built is how homeowners end up paying for the wrong scope, and it is a quick thing to check in person.

How the replacement is done

Knob and tube is not repaired. Each circuit is replaced with new NM-B cable containing an equipment ground, run from the panel to new or reused boxes at every device. Old conductors are disconnected at both ends and removed where they are accessible. Knobs and tubes buried in framing are typically left in place because pulling them causes more damage than they are worth, and they carry nothing once the circuit is dead.

Scope is driven by what is still energized. Many houses have partial knob and tube, where a 1970s remodel replaced the kitchen and the original circuits still feed the bedrooms and hallway lights. In that case only the live legacy circuits get replaced, which costs a fraction of a full rewire. Kyle traces every circuit at the panel and gives you a written list of what is knob and tube, what is not, and what each portion costs.

Insurance, permits, and documentation

Carriers in Washington ask about knob and tube specifically, and the answer they usually want is that it has been removed from service by a licensed electrician under permit. That means the paperwork matters as much as the wire. Gale Electric pulls the permit under Washington license GALEEEL790O7 and schedules both the rough in and the final inspection, so you finish with an inspection record you can hand to your agent.

Permitting runs through Washington L&I in most of Benton and Franklin County, and through the City of Richland for addresses inside city limits, depending on jurisdiction. The rough in inspection happens while the new cable is still exposed, which sets the schedule for any patching or insulation work that follows. If you are combining this with attic insulation, sequence the electrical first. Blowing insulation over a circuit that has not been inspected means pulling it back out.