What to do if you hit a cable

Learn exactly what to do, in order, if your drill bit hits a cable or pipe hidden in a wall.

WC-01Know the warning signsA hit cable often feels different before it looks different: the drill suddenly grabs, judders, or spins with no resistance, or you hear a faint crack or pop. You might see a spark, smell burning plastic, or the drill could just stop dead if it trips the power. Any one of these means treat it as a hit cable until proven otherwise, even if nothing obvious happened.

WC-02Stop the drill immediatelyThe moment something feels wrong, stop pulling the trigger and hold the drill still. Do not reverse it out and do not push forward to 'get through' — both movements can widen the damage to a cable or pipe. The beginner mistake is carrying on because the hole isn't finished; finishing the hole is no longer the goal.

WC-03Isolate the power or water before touching anythingIf there's any doubt at all, go to your consumer unit — the grey box, usually near your meter, with the switches that control power to the house — and switch off the relevant circuit, or the main switch if you're not sure which one. If you think you've hit a water pipe instead, turn off the stopcock, the valve (often under the kitchen sink or near where the water pipe enters the house) that cuts off your water supply. Do this before you inspect the hole, not after.

WC-04Check yourself and the room, not the holeBefore you look at what you drilled into, check you're not hurt — a shock can be delayed or feel like a slight tingle rather than a dramatic jolt. Look and sniff for smoke, burning smell, sparking, or water coming through the wall. If any of these are present, leave the room and call for help rather than investigating further yourself.

WC-05Inspect the hole by eye onlyWith the power or water isolated, you can look at the hole, but don't poke inside it with fingers or tools. Use a torch to see if you can spot cable sheathing, copper, or a pipe. A drill bit that's cut just the sheath but not the copper wire is very different from one that's cut through it, and that judgement should be left to a professional, not guessed by touch.

WC-06Get it professionally checked and repairedEven a graze on a cable or pipe can fail later, so call a qualified electrician or plumber rather than patching it yourself. In England, some electrical work in a home falls under Part P of the Building Regulations, meaning certain repairs must meet safety standards and sometimes be notified to building control — a qualified electrician will know if this applies to your repair. Don't restore power or water until you've had it confirmed safe.

RULES

KNOW THE RULES

Part P (England) covers certain electrical work in dwellings; a registered electrician can confirm whether a repair is notifiable.

WC-07Prevent it next time by expecting something's thereBefore your next drilling job, use a cable and pipe detector, a handheld tool that senses hidden wiring and pipework and gives a beep or light near them, and always check known danger zones like above sockets and switches. Treat a clear reading as 'nothing found by this device' rather than 'definitely nothing there' — detectors can miss cables that are deep, run in metal conduit, sit behind metal-backed plasterboard, or simply weren't installed in the usual safe zones, which is common with older or amateur wiring. The safer habit is to assume a cable or pipe could be there and drill cautiously, rather than trusting a clear scan completely.

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