Electrical help please- drilled through a cable in the wall!

Drilled a single hole in the corner of the bathroom yesterday only to discover that the supply to the upstairs light circuit runs up there!

Splendid. The circuit tripped, but when i turn it back on the lights still work.

Have left it off now and no other problems evident.

So, what needs to be done to repair? Can the wall (plaster over brick) be chased out and a junction box be embedded into the wall? I don’t think there’s a conduit, just the cable in the plaster, so pulling it through isn’t going to happen.

Am waiting a call back from a recommended electrician, but need to know what to expect and if i can do anything to make it quicker/cheaper. Very keen not to tear the house apart!

keep telling myself I should be grateful I didn’tget electricuted, but too annoyed to think that way at the moment

Thanks

Jon

Did the bulb blow ? Junction box should be fine. Just tape up any copper you can see. .Do it all the time when I drill through power cables at work , I’m not a spark so I’ll expect to be told of here later.

Oops. Not a qualified sparky so I’m prepared to be proved wrong.

As far as I know, joints in cables made with junction boxes and the like where the cables are screwed in need to be accessible. If the cables are joined permanently by soldering, brazing or crimping, you can plaster over. The worry is that you have thought it a nice place to drill a hole, someone else will too, and it could happen again.

Also, since you don’t know what’s going on in there, flip that circuit off until either the sparky has a look or you dig in yourself and make sure the wires aren’t about to short and start a fire/cause other damage.

A few choices here:
1. Plaster over and ignore it.
2. Hack out the plaster and fit a junction box. Plaster over.
3. Hack out, fit choc block in metal box and plaster over. Metal box stops anybody else drilling into it, assuming they are using a masonry bit in the drill of course.
4. Strip cable out of wall back to junction box, fit proper conduit and re-wire.
5. Get qualified electrician in.

Only one of the above is correct, but I’d go for number 3.
Hth
Marko

Ouch. I’ve come pretty close to doing this, and just remembered the beepy wall metal finder gadget at the last moment before drilling. First thing I’d do is get one of those ordered right now and use it every time you go near a wall – mine cost £7 and has saved loads of pain over the years.

Assuming you know them, and they’re not a con-merchant, I’d just get the electrician in and ask them what to do to fix it with minimal mess personally. They’ll need to have a look at the wires, see how much you’ve drilled into them etc. before they can say what to do to make it safe.

On the bright side, at least it wasn’t a water pipe.

The SKY bloke drilled through a gas pipe in my old house…. had no heating for a week in December…. scary stuff you were VERY lucky.

You can get little hand held machines that check for pipes etc that bleep don’t know how much they are?

Someone helpfully boxed in some pipes for me, after he left I noticed the lights didn’t work, obviously sent a screw through the wire tripped out the circuit. Remove cover from light switch, continuity multimeter on wire at light switch other end tried against all the screws til I found the culprit, removed screw, switched everything back on, house hasn’t burned down yet. Result!

If you’re lucky the cable will be loose in the conduit and it might be possible to splice new onto the switch end then pull it up into the attic. That’s what I would do anyway. I’ve done it when moving wall sockets.

I’ve been renovating the house for the last two years and have either put in or been around for the installation of all the water, gas and electrics. But the electrician was and idiot. He was the first to start work and I was still learning what was what.

Now we have a switch that doesn’t seem to do anything, an odd (but apparently acceptable) earth rod in the back garden and back boxes for sockets set so far back into the walls that I have to use super long screws and thread extenders just to fit the face plates.

I must have been away for the “lets hide a cable in a random corner” day.

Thanks for the ideas so far

On the bright side, at least it wasn’t a water pipe.

I’ve done that. I suppose it should have been obvious that there’s a pipe in the wall directly above a sink 🙄

OTOH I reckon a water pipe’s actually a lot less hassle. Turned off the stop cock, dug out the plaster to get to the hole in the pipe (handily the water made it easier to remove). Used pipe sealant on the pipe. Replastered the wall Hung the mirror I was putting up in the first place over the hole in the plaster.

I did exactly this and took the opportunity to add a new socket.

I did exactly this and took the opportunity to add a new socket.

I like this: turning a problem into an opportunity. An admirable attitude. 🙂

Not sure what the OP would want with a socket in the corner of the bathroom though (are you even allowed sockets in bathrooms these days?)

My neighbours just done this too, though he actually managed to blow out a cable elsewhere in the house, due to with the overload. Not a happy chap trying to locate a single blown piece of cabling on a huge circuit (whole house is apparently on one ring main), all for the sake of one screw… which he admitted wasn’t actually necessary!
(already had one in, put the 2nd to make it ‘secure’).

So count yourself lucky!

On the bright side, at least it wasn’t a water pipe

Exactly, what you can’t see can’t hurt you 😐

Do it properly, the cable should be oval conduit or behind channel. Find the ends and see if it moves. Attach a new length of cable to one end and draw it through and re connect.

I must have been away for the “lets hide a cable in a random corner” day.

If he did put that in, rather than it being existing wiring, and didn’t put in conduit or with a protective strip over it then I’d be calling him and asking if he would like to come and repair it for free or would he rather you contact others who might be interested in his workmanship.

This is what i would do…and yes i am a sparks.

Chop out enough plaster to pull the cable out and cut it in half. Then strip back the outer insulation just enough to through crimp each core and tape up (well). Clip back against the wall and re-plaster. This is the easiest solution….not necessarilly the best or most acceptable from a Part P point but still ok. Capping and conduit wont really stop you from drilling into cables they just act as a draw through to remove cables and to stop the plasterers trowel from cutting the cable. An RCD on the circuit will negate the need for mechanical protection.

Cut the cable in the attic once switched off, and re feed a new cable some other way to where it needs to go , either in conduit or another route.

A chap a few years ago, just married and he got a family crest shield as a wedding present, put it up under a wall lamp, problem was it had 2 crossed swords on it, he switched the light on , called his new wife, and she pointed out it wasnt quite level, he touched the sword to move it, was electrocuted and thrown across the room, he had drilled a cable before RCD, s

An RCD on the circuit will negate the need for mechanical protection

😯

Really!!!! are you entirely sure about such a broad statement????

The best thing to do is to get a man in, it really depends on the damage that has been done to the cable. You might be fortunate enough not to have damaged the conductor and if that is the case then a repair of the insulation MAY be possible. If the conductor is damaged then the only proper solution is to either replace the cable or install an accessible joint box.

The only real way for they guy to find out is to remove some of the plaster around the drill hole to see.

There is an RCD on the circuit, which presumably contributed to me not having a brand new spiky hair-do.

Thanks for the other ideas. Replacing cable and/or putting new conduit in would be a ballache and would mean chasing in a channel all the way up the wall. Also, floor above is converted loft so would mean lifting carpet and trying to lift the well secured chipboard floor to get access.

Might try excavating the hole tonight and see how bad the damage is. Cable detector on shopping list.