Knob-and-tube in Fairfield & James Bay: what your insurance won't tell you

Fairfield, James Bay, Oak Bay South, Fernwood and Rockland are full of houses built in the early 1900s. Homes wired before about 1950 typically used knob-and-tube.

Knob-and-tube (K&T) runs the hot and neutral as separate wires on ceramic knobs along the joists, and through ceramic tubes where they cross framing. It met code and was safe when it went in. Many insurers won't cover it now.

Why insurers push back

1. It can't handle modern loads

K&T was sized for a 1920s house: a few lights, a radio, an iron, later a fridge. The wire is 14-gauge with rubber-and-cloth insulation rated for 60°C. Run a space heater on it and the wire heats up, and that insulation is now 80–110 years old.

2. Attic insulation

Many older Victoria homes have had attic insulation added since the 1970s, often right over the K&T. The wiring was designed to shed heat into open air. Buried in cellulose or batt, it runs hot until the wire's insulation breaks down and the copper is bare.

3. No ground

K&T has no equipment grounding conductor, so every outlet on it is ungrounded. It also makes it harder to add GFCI and AFCI protection properly, and BCEC 2024 expands where AFCI and GFCI protection is required.

Many insurers won't cover knob-and-tube, or want a written commitment to rewire, often within 6–12 months.

How to tell if you have it

If your Greater Victoria house was built before 1950, assume it has K&T until someone checks. Many pre-1950 homes in Fairfield, James Bay, Rockland and Oak Bay South still have some, mostly in the attic and the second-floor bedroom walls.

• White ceramic knobs. About the size of a wide thumb, along attic joists or rafters, with wire tied to them.
• Porcelain tubes. White tube ends sticking out about 1 cm where a wire passes through a joist.
• Two-prong outlets. If they were never converted, there's often K&T or early ungrounded wiring behind them.
• Cloth-wrapped wires in the basement or attic.
• An old panel fed by cloth-and-rubber-wrapped wires. FPE Stab-Lok panels often went in on top of K&T during 1970s upgrades.

What a rewire involves

For a typical Fairfield two-storey (about 2,000 sq. ft., 3 bedrooms, 1.5 baths):

1. Assessment. After 80+ years of patches and suites, heritage homes are almost never all K&T. We find every K&T run so all of it gets replaced.
2. Panel. Many K&T rewires include a panel upgrade, usually to 200A. See our panel upgrade article.
3. Phased or full. If you're living there, we go one or two rooms at a time. An empty house, or one mid-renovation, gets done all at once for noticeably less.
4. New wiring. New NMD90 (Loomex) cable fished through the walls, new boxes, outlets and switches, GFCI / AFCI per BCEC 2024.
5. Permit and inspection. Permitted and inspected room by room or at completion.
6. Insurance letter. A signed letter from the contractor that confirms no knob-and-tube remains in service. That's what your insurer wants.

What affects the cost

Square footage drives the cost, then the number of floors and how much protection and patching the finishes need (plaster costs more to work around than drywall). Every rewire is quoted after an on-site assessment. What moves the number:

Phased work in an occupied home generally costs more than a full rewire in a vacant one. Many rewires also need a panel upgrade, plus permit fees.

How phasing works

An occupied rewire runs in four phases over 3–6 weeks:

1. Panel and service. 1–2 days. The house switches to the new 200A service, with temporary kitchen and bath circuits.
2. Main floor. 4–7 days. Kitchen, living room, dining room, main bathroom. This is the most disruptive week, and many people stay elsewhere.
3. Upper floor. 3–5 days. Each bedroom opened, fished and patched.
4. Basement / suite / finishes. 2–4 days. Cleanup, final inspection, walkthrough.

Power stays on room by room, except on panel-swap day.

What moves the price

1. Lath and plaster

Fishing through plaster is slower and patches are harder to hide. Plan on more labour, plus a heritage finisher to match the texture.

2. Condition of the existing wiring

All knob-and-tube comes out, no matter what shape it's in. Brittle wire insulation, runs buried in attic insulation and decades of patches all add time to the job.

3. Access

Attic access and an unfinished basement cost far less than cathedral ceilings and a finished suite, at the same square footage.

Dealing with your insurer

1. Ask for one renewal. Some insurers will renew once with the K&T flagged while you arrange a rewire.
2. Get a written quote from any TSBC-licensed contractor. That's often enough.
3. Propose a schedule. Many insurers want a written commitment to rewire, often within 6–12 months.
4. Send the completion letter. It confirms no knob-and-tube remains in service.
5. Keep photos of the attic, basement and opened walls, before and after. We photograph as we go.

FAQ

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