Why is my old unsheathed cable dangerous and when must I replace it – Advice from Electriman, North London Electricians

## What Is Old Unsheathed Cable and Why Is It a Problem?

If your home was built or last rewired before the 1970s, it may contain electrical cables that are now considered life-expired and potentially very dangerous. The most common types are:

- **Rubber-insulated cable (pre-1966):** The rubber insulation dries out and cracks over decades, exposing live conductors.

- **Lead-sheathed cable:** Heavy, inflexible, and prone to cracking — the lead outer can corrode and fail.

- **Early PVC wiring (1960s–70s):** Although better than rubber, older PVC also degrades and can become brittle.

- **Vulcanised India Rubber (VIR) cable:** A very early insulation that crumbles when touched.

- **Aluminium wiring:** Used briefly in the 1960s–70s; prone to overheating at connections.

**Why is it so dangerous?**

- Degraded insulation can no longer reliably separate live conductors from each other or from earthed metalwork, creating shock and fire risks.

- Old wiring predates modern RCD protection, meaning there may be no safety device to disconnect a fault quickly.

- Crumbling insulation can ignite surrounding materials — many house fires are attributed to aged wiring.

- The wiring was designed for lower electrical loads; modern appliances place far greater demands on the system.

**What can you check safely (without touching anything)?**

- Look in your consumer unit (fusebox) — old rewireable fuses rather than modern MCBs and RCDs are a stron

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Electriman covers Mill Hill, Barnet, Finchley, Edgware, Enfield, Watford and surrounding areas. All work is Part P certified and fully insured.