damaged cable

18 Aug 2007
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United Kingdom
Stupidly i have drilled into a cable buried in the wall :oops: i have chased the cable out to take look, and both sides of the cables insulation has been nicked slightly exposing the live and neutral conductors but not damaging them.

Can i just wrap the cable in grey insulation tape?

Or should i crimp the wires with these


Using these


Are you allowed to have crimps buried in the wall?

If so once i have crimped the wores shouuld i them wrap them in grey insulation tape?
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First of all is the cable in a safe zone? i.e. running vertical/horizontal to the switch/socket that it is supplying or within 150mm (6") of a corner. If yes then you are a 'Silly Billy'! :LOL:
If it is NOT in a safe zone then it will need to be compltely replaced to run in one. If you are not a spark (which I suspect), then you will need to get one in to do it for you.

Lets assume it is in a safe zone then yes you can use the crimps making sure you have no protruding bare wires but do not use insulation tape. Use heat shrink sleeving overlapping the complete joint by at least 10 mm each side. But do make sure the copper conductors are NOT DAMAGED AT ALL. If they are you may be lucky enough to make the cut to fit the crimps where the damage is.

It goes without saying that you make sure the power is completely OFF before starting.
you need the blue crimps not red

you must not use sticky tape

you can oversleeve with heat-shrink sleeving. A hot air paint-stripper gun will shrink it. A hair drier is not hot enough.

For neatness stagger the joints so that you do not have all the crimps in a bundle

Remember to slide the sleeving down the cable before you crimp the joints

Practice with your ratchet crimper first. You should not be able to pull the crimps apart by hand.

The ratchet crimper in your link is not the right one. You need one for red/yellow and blue insulated crimps. the capacity range is 0.5mm sq to 6mm sq. The jaws will have red yellow and blue notches.

edited: too slow again :mad:
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no 12mm

yes if you're very careful and quick

they would do

uninsulated crimps

IF the cables have been damaged why does it need crimping?

The insulation has been damaged so surely only the insulation needs replacing?

Putting crimps in it will surely only be making an unnecessary connection in the cable that can in the future cause difficulties.

Perhaps the Original poster can give a picture of the cable & its damage?
I have used Alfa tape on occasion instead of heatshrink. Its very similar to self amalgamating tape, which i use on the F plugs on sat dishes etc.
And what is wrong with using insulating tape?
After al its "insulating" ? wrapping several turns around will give the same effect as the thick coat of the original insulation?
And what is wrong with using insulating tape?
After al its "insulating" ? wrapping several turns around will give the same effect as the thick coat of the original insulation?

Because the adhesive on insulation tape tends to dry out with time and then starts to unravel and fall off making it 'non-insulating tape'. It's also leaves a sticky mess all over the cables after you've spent ages getting the stuff off which is almost certainly going to annoy anybody who needs access to the joint in the future... :rolleyes:
Am I missing something?

The OP said that both L & N insulatioon had been damaged. To my mind, this means the drill bit has gone through the middle of the cable, severing the cpc??
Not if the cable was actually sideways(twisted) in the wall.

But thats why I asked for a photo, to show exactly whats been done to it.

Fair enough about the tape, but that's cheap crappy tape though, good quality tape will usually last for many years esp if it has many turns over it & is unlikely to come undone if its plastered over surely?

I'm sure that you all have a roll in your toolbox somewhere :D

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