Knob and Tube Wiring Replacement in Kingston

The wiring hiding inside Kingston's century homes

Kingston is one of the oldest cities in Ontario, and it shows in the housing stock: the limestone and brick homes of Sydenham Ward, Portsmouth Village, Williamsville, Kingscourt and the Inner Harbour were largely built before 1950 — which means they were built with knob and tube wiring. Two separate strands of rubber-and-cloth insulated copper, strung through ceramic knobs and tubes, with no ground conductor anywhere in the system. It was fine engineering for 1925. It is a problem in 2026.

The issue isn't only age. Knob and tube was designed to run in open air; when attics get filled with blown-in insulation, the wires overheat. The rubber insulation turns brittle and flakes off the conductor. And after a century of renovations, most systems carry decades of amateur splices — taped junctions buried in walls, modern circuits tied into 1920s wiring, all of it invisible until someone opens things up. That's why our page is knob and tube safe? is the most-read on this site: the honest answer is "it depends on things you can't see."

Why the file lands on your desk with a deadline

A knob-and-tube system can sit quietly for decades. Then one of two letters arrives, and everything accelerates:

• The insurance letter — most standard insurers now refuse new policies on homes with active knob and tube, or issue coverage conditional on replacement within 30–90 days. The alternative is high-risk coverage at a punitive surcharge. Full details on our insurance page
• The home inspection — you're buying or selling a century home, the inspector finds knob and tube, and suddenly the buyer's financing and insurance both hinge on a rewiring plan with real numbers attached
• The renovation permit — you open a wall for a kitchen or bathroom project and code requires the old wiring in that section to be brought up to standard
• The mystery symptoms — flickering lights, warm switch plates, fuses that blow on hair dryers: a 60-amp service built for 1925 loads meeting a 2026 household

It's the same mechanism as vermiculite insulation or an old buried oil tank: it's not the law that forces the work — it's the institutions that insure and finance the house. Once the letter exists, the question is no longer "if" but "how fast, and at what price."

What replacement actually involves (and what it doesn't)

The fear is always the same: torn-open walls. The reality in most Kingston homes is far tamer. Experienced crews fish new grounded cable through wall cavities from the basement and attic, using small strategic openings that get patched. A typical century home takes 3–10 working days, livable throughout. The work runs under an ESA permit, finishes with an ESA Certificate of Inspection, and that certificate goes to your insurer. Costs are on our cost page — real ranges, published, no "call for pricing" games.