Spokane boomed in the decades around 1900, after the Great Fire of 1889 cleared much of downtown and the railroads brought money and people. Whole neighborhoods went up in a few decades: the mansions of Browne’s Addition, the Craftsman homes of the South Hill and Cannon Hill, the bungalows of Logan, Garland and the Perry District. Those houses were wired with the technology of the day, and in many of them, some of that wiring is still there.
What knob and tube is
Knob and tube wiring uses single insulated copper wires, one hot and one neutral, run separately through the framing. Porcelain tubes protect the wires where they pass through joists and studs, and porcelain knobs hold them away from the wood along the way. Connections were made by twisting and soldering wires and wrapping them with tape. It was installed from roughly the 1880s into the 1930s and was considered good work at the time.
How to tell if you have it
- Look in an unfinished attic or basement for porcelain knobs and tubes with separate wires.
- Two-prong outlets throughout the house are a clue, though not proof.
- Cloth-covered wires, sometimes black and crumbly.
- Lights with pull chains and very few outlets in older rooms.
- A fuse box, or a newer panel with a few old circuits feeding into it.
Is it dangerous?
Knob and tube isn’t automatically dangerous, but after a century, problems are common. The rubber and cloth insulation gets brittle and cracks. Past owners spliced into it, often badly. It has no ground wire. And it was designed to shed heat into open air, so when attics are filled with blown-in insulation, as many Spokane attics have been to fight winter heating bills, the wires can run hotter than intended. Modern loads like space heaters and microwaves on old circuits add to the strain.
Don’t add blown-in insulation over live knob and tube without an electrician’s evaluation. Washington’s rules on insulating around it are specific, and it’s one of the most common reasons it needs replacing.
Insurance and home sales
Many insurers ask about knob and tube and fuse boxes. Some won’t write a new policy until an electrician evaluates or replaces it; others charge more. Home inspectors routinely flag it, and buyers often ask for a credit or replacement. If you’re selling an older Spokane home, an electrician’s report can help.
| Option | When it fits |
|---|---|
| Evaluate and leave in place | Wiring is intact, not buried in insulation, and lightly loaded |
| Replace high-risk circuits | Attic runs under insulation, kitchens, baths, damaged sections |
| Full rewire | Widespread damage, planned remodel, insurance requirement |
| Rewire plus panel upgrade | Fuse box or small service with old circuits |
Questions to ask an electrician
When an electrician evaluates old wiring, ask them to be specific. Which circuits are still knob and tube, and are they live? Is any of it buried in insulation? Are there amateur splices or overloaded circuits? Which repairs are urgent and which can wait? Can the work be phased, and will it be done under a permit? A clear written report helps with insurance, with buyers if you sell, and with planning the work over time. In Spokane, permits inside city limits come from the City of Spokane’s electrical program, and a licensed contractor handles the paperwork.
What a rewire involves
Rewiring an old plaster house is careful work, not demolition. Electricians fish new cable through walls from the attic and basement, use existing paths when they can, and cut small openings where needed. Many owners do it in phases, starting with the riskiest circuits. Our rewiring guide walks through the process, and the panel upgrade guide covers the service side. For an overview of electrical work in the city, start with our guide to electrical work in Spokane.