Switches and sockets - Conversion from flush mount to surface mount

Discussion in 'Electricians' Talk' started by carlosbeneto, Dec 4, 2020.

  1. carlosbeneto

    carlosbeneto New Member

    Good afternoon everyone!

    I'm here looking for suggestions of how to do this in a practical and legal way. I'm not an electrician but I'm fairly well practiced in other fields having done some motorsport wiring and electronics, I'm not overly familiar with residential code though.

    The situation is the following. I have a 1G double light switch and a 2G socket units on a wall in the lounge. I'm going to cover this wall with brick slips (20mm thick brick faces cut from real bricks - very thick, irregular tiles effectively).

    [​IMG]

    [​IMG]



    Two main questions arise from this. I'm going for an industrial style, and part of the plan is to have surface mount, galvanised boxes for said sockets and switches. So the first question is... What is the best (and legal) way to bring the wires that go into the existing recessed back boxes into the new surface mount ones? Do I take out the existing back boxes and bring the wire through the bricks like in an external install with armormed cable for example? That raises the question of extending the existing wires which I'm sure will be too short.

    It's my understanding I can't simply leave the back box and tile over it, I think back boxes are meant to be accessible? Any guidance on how to this neatly and legally is welcome.

    For further clarity these are the switches in question:

    [​IMG]

    Now on to the second question. As you can see these new switches and sockets are designed for 20mm conduit. The existing equipment has two switches for two separate lights (dining area and living area). This new one has three as I want to add a third light circuit along the wall by using 20mm conduit. Now, there's no need to modify the existing wiring to the current lights beyond question 1. However, for this new light the intention is to run it in 20mm conduit, making it easier to fit after the bricks are in and also turning it into an "industrial" feature. I believe I can branch off the existing light circuits with no issue? Same question with sockets (as long as they're not a spur already, which I'd be surprised if they were).

    Long post I know, I hope it all makes sense!

    Thanks
     
  2. The Happy Builder

    The Happy Builder Screwfix Select

    Easiest to take up the floor boards in the room above, cut the existing cables off and rewire in conduit from there.
     
  3. carlosbeneto

    carlosbeneto New Member

    I did think of that, but the upheaval is huge! I thought of maybe fitting one of those round galvanised junction boxes up high, close to the ceiling directly above the existing switches. That would allow pulling the cable through the plaster there and then go to the switches through the conduit... But that doesn't solve the issue with the sockets...
     
  4. The Happy Builder

    The Happy Builder Screwfix Select

    There probably is not a neutral on the lighting cable at the switches, so you cannot just extend from there, you may need to get back to the light fitting on the ceiling.
     
  5. carlosbeneto

    carlosbeneto New Member

    After some more investigation there is neutral, live and ground at the switches. I'm in luck in that front I think!
     
  6. DIYDave.

    DIYDave. Screwfix Select

    Nice ideas - get it right and will look fantastic !

    Brick slips around 20mm thick and add adhesive, you may be in luck and wires could be long enough for new surface mount accessories

    If not, extend cables inside new surface mount boxes using Wagos, 221s for instance

    Those metal boxes are plenty deep enough for the connectors to sit in and act as an enclosure

    I’m diy only, see what the pros think
     
  7. carlosbeneto

    carlosbeneto New Member

    Ok! Making progress on this (slowly). So I've done the brick slips (they look great thanks for asking :D). I think I'm luck with the wiring, as this is neutral at the switch (someone correct me if I'm wrong). The blue neutral wires are all terminated inside the back box and not connected to the switches in any way.

    [​IMG]

    I'll be using a vintage style (although modern BS EN approved) triple gang surface mounted switch as below. Both the faceplate and housing have earth tags, so I'll connect those to the existing earth choc block you can see above.

    [​IMG]


    Someone please confirm my homework. The idea is to add a third light switch for a few LED bulbs along the wall. So I'll add the third switch by jumping the common from the neighbouring switch (as it is now), then live to the lights via external 20mm galvanised conduit (with all the appropriate bushings, etc), neutral from the lights to the choc block (I'll probably replace this with Wagos) and earth the conduit to the choc block.

    [​IMG]

    I hope that all makes sense! I'm pretty certain this should work safely and be compliant. Everything is accessible and follows the standards. I'll be using stranded wires for in the conduit for flexibility, from what I've read this is the best practice.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice