What it is: Early-1900s wiring with no ground conductor, run on ceramic knobs and tubes.
Why it matters
It lacks grounding, becomes brittle with age, and is dangerous when buried in insulation; many insurers will not cover it.
Why it's common in Bloomington
Seen in Bloomington's oldest pockets and in neighboring South Minneapolis and Hopkins bungalows.
Signs to watch for
- ceramic knobs/tubes in the attic or basement
- two-prong outlets
- cloth-insulated conductors
What we check during the inspection
We document any active knob-and-tube observed in accessible areas.
How it's typically corrected
Replacement by a licensed electrician; partial abandonment must be verified, not assumed.
Concerned about knob-and-tube wiring in a home you're buying or selling? Get a free instant quote and we'll evaluate it as part of a full inspection.