Nail through electric cable

[deanoc]

Hi Guys

So long story short, was ensuring my floor boards were secure prior to carpet fitting Saturday and I decided to tap a nail in.... Bang?!?!

Turned off fuse board, lifted floor board and the nail was buried in the supply for the shower (16mm cable) removed and turned everything back on

Everything is working as it should

Does the cable need to be repaired or replaced?

My electrician is on holiday but is carry out other works (New circuit in living/dining room) in my house on his return... Just want an idea of what to do

Thanks in advance guys

 

[Robin0577]

Ideally the entire cable should be replaced.

Depending on the circumstances, it may be possible to replace part of the cable using maintenance free joint(s). Traditional screw terminal joints are not permitted if they are to be inaccessible.

 

[sparkwright]

You CANNOT leave the cable as it is.

That bang signifies a short has occured, so a wire will in some way be damaged.

Just because it works doesn't mean there is a fault.

There will be a serious fault there.

Turn the shower circuit off at the mains, and do not use the shower until it's been repaired.

16mm? How have you measured the cable?

Though there are some circumstances why a shower should be wired in 16mm2, in real life it rarely ever is done in cable that big.

 

[deanoc]

You CANNOT leave the cable as it is.

That bang signifies a short has occured, so a wire will in some way be damaged.

Just because it works doesn't mean there is a fault.

There will be a serious fault there.

Turn the shower circuit off at the mains, and do not use the shower until it's been repaired.

16mm? How have you measured the cable?

Though there are some circumstances why a shower should be wired in 16mm2, in real life it rarely ever is done in cable that big.

I've emailed my usual sparky and steady switched off the fuse for this circuit

I assumed it was 16mm the sheath is about 20mm wide, think it was a DIY job before I purchased the house (as per everything else) the cable is absolutely massive!!!

Seen as I'm having other work done might just ask my sparky to replace the cable from the board to the shower... I guess this is the safest and best solution

 

[sparkwright]

If it's relatively easy to replace, change it completely.

If it's likely to get nailed through again, then it would make sense to replace and find a better route.

Was the cable notched in the top of the joists?

Probably better to drill holes through the joists lower down.

 

[deanoc]

It's not notched, but the holes are only 20mm from the top of the joist!

I've already found a new route (which doesn't include surface mounting like it is now in the hallway)

One question though, current cable is routed to the loft then comes down into the bath room... Is it ok to go straight to the bathroom then up to the shower (and on from there to the isolatator switch)? This route is shorter and simpler!!

 

[EFLImpudence]

Yes, but you need to go to the switch first (and then back to shower).

 

[Taylortwocities]

And the cable route in walls and ceilings must be run in recognised 'safe' zones. See relavent sections in the WIKI //www.diynot.com/wiki/Electrics:Installation-Techniques

 

[flameport]

Seen as I'm having other work done might just ask my sparky to replace the cable from the board to the shower... I guess this is the safest and best solution

Safest certainly.
Best would be to throw the electric shower away and fit a proper one.

 

[kai]

The old shower cable was clearly NOT run in a safe zone - it was installed by a DIY person judging from very poor routeing of the old cable, through a danger zone!

 

[Iggifer]

The old shower cable was clearly NOT run in a safe zone - it was installed by a DIY person judging from very poor routeing of the old cable, through a danger zone!

Well that's not true. Firstly there are no 'safe zones' for cables in floors. Yes it should be 50mm deep or protected, but I have seen literally thousands of holes and notches, done by professional electricians, that are not.

Things just used to be done differently.

 

[conny]

In my first house which I bought in 1979 all the cables ran directly upwards behind the front door, branching off under the first floor floorboards and the remaining upper floor lighting cables continuing up into the loft. Two years later I had an improvement grant carried out including a full re-wire. All cables were dropped below the suspended ground floor and re-routed upstairs behind the internal door carcases of the lounge and front bedroom. This was only discovered when the joiner decided to put an extra screw in the bedroom door frame and there was a loud bang. Builder wasn't happy as he had subbed the work out and had to get him back to re-route everything.