Extending T&E cable behind plaster

[glynn]

I have recently put an extension on the side of the house, and our old kitchen has now become a dining room.

In this new dining room, all of the old power outlets are at the mid height (for kitchen units), but now if possible I want to convert them to normal low level outlets for dining room use.

What I would like to know is, is there any way to extend the cables (whilst still complying with Regs) down to low level, to leave a invisible joint behind plaster??? Or am I forced to remove the old cable to ceiling height, and install junction boxes in ceiling, and run new cable down wall?

The reason I ask is that the floor upstairs is varnished floorboards, so I'm a little reluctant to pull these up to install new junction boxes in the ceiling void.
Regards

Glynn

 

[dw3101]

Only way I can think of is to fit a blanking plate and use terminal blocks in the box.. or leave sockets there..

I would leave it until you decide to decorate..

David

 

[dingbat]

Wiring Regs - reg 526-04-01:

Except for the following, every connection and joint shall be accessible for inspection, testing and maintenance:
(i) a compound-filled or encapsulated joint
...
(iii) a joint made by welding, soldering, brazing or compression tool...

There you go - you can plaster over the joints mentioned above, but if you are going to use crimps (compression tool) make sure you use a good ratchet crimper.

 

[mackeral]

can t+e still be plastered into the wall? Does it not need mechanical protection?

 

[ban-all-sheds]

http://www.niceic.org.uk/downloads/concealedcables.pdf

http://www.niceic.org.uk/downloads/C5-43.pdf

 

[plugwash]

Wiring Regs - reg 526-04-01:

Except for the following, every connection and joint shall be accessible for inspection, testing and maintenance:
(i) a compound-filled or encapsulated joint
...
(iii) a joint made by welding, soldering, brazing or compression tool...

There you go - you can plaster over the joints mentioned above, but if you are going to use crimps (compression tool) make sure you use a good ratchet crimper.

is there an (ii)?

 

[dingbat]

is there an (ii)?

Indeed there is (which is why I used an ellipsis "...") It refers to cold tails and heating elements and has nothing to do with the question so I left it out. (There's also a (iv), to do with joints forming part of installed equipment - those IEE boys have thought of everything )

can t+e still be plastered into the wall? Does it not need mechanical protection?

Yup. T & E already incorporates 'mechanical protection' by dint of its outer sheath. It only requires additional protective measures if run outside 'safe' zones, but good practice dictates that you would at least use capping.

 

[glynn]

Gents

Many thanks for the advice, I am handy with a soldering iron so soldering the joints will be no problem.

If soldering, what is an acceptable method to insulate the joints, is it OK to wrap with loads of insulation tape??

Regards

Glynn

 

[dw3101]

Heatshrink on each core and heatshrink over the lot would be my choice.

if you have sockets more than 1m apart, does anyone run horizontally?

I allways try and run up and across.. then back down. (where possible)

David

 

[mildmanneredjanitor]

Pardon me for interrupting, but aren't the cables coming up the wall to the sockets? This is the normal convention.

If you are moving the sockets down the wall, they will need to be trimmed...

 

[AdamW]

With concrete floors they are often run down from the ceiling, for reasons of ease of access.

Not sure I would want to solder the connections mind, doesn't seem like a healthy way to make connections that are suitable for a 32A ring. Resin filled boxes are about £18 each, or a ratchet crimper is £20-30.

The issue with putting JBs in the ceiling is they are supposed to be accessible. Not really the case if you can't lift those floorboards without major disruption. But as you have bare floorboards up there, you would hopefully see any smoke coming out of the floor soon enough anyway

If it were me, I would try a few practice goes on some scrap T&E with a crimper, to make sure I was happy with using it, then do it for real. I would then use tape around the joints, and capping over the joint before plastering over.

 

[ban-all-sheds]

If it were me, I would try a few practice goes on some scrap T&E with a crimper, to make sure I was happy with using it, then do it for real. I would then use tape around the joints, and capping over the joint before plastering over.

Good plan, apart from the tape.

 

[AdamW]

Perhaps I should have phrased that better:

I would crimp the joins, THEN wrap them in tape

Or would heatshrink be better?

 

[Damocles]

self amalgamating tape?

 

[dingbat]

self amalgamating tape?

Brilliant stuff , that. Used to use it to waterproof cable splices on 128 channel-twisted-pair cables in the siesmic game back in the eighties - worked fine right through the Thai rainy season, so I reckon it'll hold up against a poxy bit of plaster.