Author Topic: Extending wall light cabling within the wall  (Read 1443 times)

Extending wall light cabling within the wall
« on: 17 July, 2019, 10:32:10 am »
Number one son wants to extend the lighting circiut to move a wall light about 150mm to the right.  There are 50mm tails currently sticking out of the wall for the existing light.  Is it OK to chisel out a channel and lay a new length of cable in and use a chocblock terminal box to join them?

Ideally we would get into the ceiling void and drop a new cable in but that's not an option.

Thanks

Re: Extending wall light cabling within the wall
« Reply #1 on: 17 July, 2019, 10:41:09 am »
A proper electrician may be along shortly to point out the error of my ways but here goes...

The short answer is "yes" BUT that is how a sparky would have done it 20 years ago.  Chocblock is frowned upon nowadays and a proper sparky would use crimps or possibly the newer "Waygo" type terminal blocks which terminate the cable ends without using screws.  One type uses some sort of internal spring to grip the end of the cable and it is very difficult to get the cable back out and the more modern types use a small lever to trap the end of the cable and so can be re-used.

Feanor

  • It's mostly downhill from here.
Re: Extending wall light cabling within the wall
« Reply #2 on: 17 July, 2019, 10:53:09 am »
AIUI:

Chock block should only be used if it remains accessible eg in a wall box with a removable cover.
If it's going to be buried and inaccessible, then AIUI, it needs to be something like crimped or solder-and-heatshrink.

Re: Extending wall light cabling within the wall
« Reply #3 on: 17 July, 2019, 10:57:14 am »
A proper electrician may be along shortly to point out the error of my ways but here goes...

The short answer is "yes" BUT that is how a sparky would have done it 20 years ago.  Chocblock is frowned upon nowadays and a proper sparky would use crimps or possibly the newer "Waygo" type terminal blocks which terminate the cable ends without using screws.  One type uses some sort of internal spring to grip the end of the cable and it is very difficult to get the cable back out and the more modern types use a small lever to trap the end of the cable and so can be re-used.

Not a sparky, but regardless of how the connection is made to the extension, I think you are still going to need to leave a blanking plate in place rather than hiding it under render, so that someone working on the circuit in the future knows that the supply to the light goes sideways before going vertically.

Just my 2p.

(Personally, I'd rather do the job properly and put a new vertical cable run in, but my philosophy has been informed by having to correct the assorted DIY projects that previous owners of my house have perpetrated.)
"He who fights monsters should see to it that he himself does not become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." ~ Freidrich Neitzsche

Re: Extending wall light cabling within the wall
« Reply #4 on: 17 July, 2019, 11:11:48 am »
What Spesh said.

Horizontal mains runs are the work of the devil bodger.
<i>Marmite slave</i>

Re: Extending wall light cabling within the wall
« Reply #5 on: 17 July, 2019, 11:12:16 am »
All good thoughts, thanks.

Re: Extending wall light cabling within the wall
« Reply #6 on: 17 July, 2019, 11:27:59 am »
L-shaped cable runs are technically not allowed in the middle of a wall due to these rules, although I get the feeling this is routinely ignored.

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: Extending wall light cabling within the wall
« Reply #7 on: 17 July, 2019, 11:29:53 am »
The run would be best protected too, with a galvanised metal capping. That would hold up a driller in the future for a little while...
It is simpler than it looks.

madamemugwump

Re: Extending wall light cabling within the wall
« Reply #8 on: 17 July, 2019, 11:41:58 am »
Horizontal mains runs are the work of the devil bodger.

Indeed, convention exists for a reason.

I'm in the process of removing decades old render from a wall. Beneath lies buried cable, some of it horizontal, some of it vertical. Some of it going to places as yet unknown. There have been buried choc blocks too, all bound up in winds of electrical tape. Call me a coward but I've switched off the power at the main fuse box just to be really really safe.

Sadly, the thing about convention is it is only that. And even laws/regs get ignored. YOU might know what you're doing, and if you're lucky you might even remember it a couple of years down the track but it can be a hazardous maze for someone coming new to it. If you're going to join cable and change the run direction then it'd be nice/safer to contain it in a junction box with a cover plate. It might not suit the aesthetics but that's another issue!   

Re: Extending wall light cabling within the wall
« Reply #9 on: 17 July, 2019, 11:47:53 am »
Cables pass directly though the wall into garage the other side of the wall.  So easy to change.


Kim

  • Timelord
    • Fediverse
Re: Extending wall light cabling within the wall
« Reply #10 on: 17 July, 2019, 12:35:55 pm »
What Spesh said.

Horizontal mains runs are the work of the devil bodger.

+1

Burying connections in a wall is definitely a no-no, too.  Needs a blanking plate.

Forget choc-blocks, Wago connectors (AUIU the 221 series is the state of the art) are a thing of beauty and a joy forever.  Easier to work with and less inclined to loosen over time.


Cables pass directly though the wall into garage the other side of the wall.  So easy to change.

In which case that's much easier than bodging.   :thumbsup: