To clip or not to clip ... this is my question

Discussion in 'Electricians' Talk' started by rogerk101, May 22, 2020.

  1. rogerk101

    rogerk101 Screwfix Select

    In many countries around the world, it is advised not to clip your cables to the studs in a drywall or similar situation, the reason being that if someone drives a nail or screw into the wall, the cables are reasonably free to move out of the way of harm ... whereas if they're clipped/attached firmly then the screw or nail is more likely to damage the cable.

    I imagine this has been discussed, and possibly even advised about, in the UK, but I've yet to see anything in 'the rules'.

    Thoughts? Opinions? Pointers to regulations?
     
  2. Coloumb

    Coloumb Screwfix Select

    So long as he cables are in the permitted zone I don't see what difference it makes. If some idiot bangs in a nail where it shouldn't be who's fault is that? 7671 makes no reference to clipping or not so really its personal preference.
     
  3. Bogle Crag

    Bogle Crag Screwfix Select

    I wired a block of flats in 86, the consultant said no clipping in stud work for that reason and possibly to save man hours, it was also the first time I was told to fit accessories inside kitchen units
     
  4. Makes a difference to installation method, clipping to the stud would make it 103 and vastly cutting down the current carrying capacity, assuming of course the wall was filled with insulation.
     
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  5. Lectrician

    Lectrician Screwfix Select

    When clipping cables in a stud wall, you’re likely to pull them out of the permitted zones. Leave them loose. Your hole in the head or sole plate should be inline with your accessory box.
     
  6. Bob Rathbone

    Bob Rathbone Screwfix Select

    Long ago and far away in a distant galaxy (16th Edition), it was not required to clip cables when they rested on a surface and would not be disturbed or tripped over. Not loft spaces, but does include between floors and in stud wall voids.
     
  7. unphased

    unphased Screwfix Select

    Has he got a hole in his head then :eek:
     
  8. Paco de Lucia

    Paco de Lucia Member

    Is it required now? For cables in floor voids for example....if so it makes a mockery of any use of rods!
     
  9. Bob Rathbone

    Bob Rathbone Screwfix Select

    Exactly, I do not have an 18th Edition as I am now retired, I would have to buy it myself!. I would assume that this has not changed as it would mean we could not 'fish' across ceilings etc.
     
  10. unphased

    unphased Screwfix Select

    Cables just need to be supported, how they are supported is a matter for interpretation. Ceilings support cables perfectly well. There is a requirement to support cables where they might hang down in a fire but again that is open to interpretation. Cables hidden from view and inaccessible cannot be clipped anyway.
     
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  11. Lectrician

    Lectrician Screwfix Select

    Cables are not meant to be laid on the ceiling board, but everyone does it in retrofits. The regs specify the cable must pass through joists with a minimum of 50mm cover from the bottom of the joist. The reg is a little woolly when it comes to the space between joists. It is often assumed the 50mm is a requirement here too, but the reg is worded something like: "The cable installed above a ceiling is to be run in such a place that is will not be damaged by the ceiling or its fixings." We are encouraged to take this as 50mm above the ceiling board too. More so when the cable is clipped to a joist - clip it above 50mm to ensure it doesn't get nailed or screwed by a poorly positioned fixing of the ceiling. Boarders to miss the odd joist.
     
  12. Bob Rathbone

    Bob Rathbone Screwfix Select

    I agree with you for first fix new build, the cables should be clipped, but only sufficiently to keep them out of harms way during board fixing. The distance set for minimum hole position from the top of the joists is to avoid damage by floor board fixings. For retro fit, clipping in the floor void is not required and would be difficult in most places, but the requirement for holes when cables pass through joists must be observed. So you cannot use slots in joists (without a protection plate) or holes that are too close to the top, or bottom of the joist.
     
  13. unphased

    unphased Screwfix Select

    You can use slots, or slotted holes, in joists. I think what you meant is notches in the top or bottom of the joist. Holes should always be drilled at or as near as possible through the neutral bending axis of the joist, which is the centreline.
     
  14. Bob Rathbone

    Bob Rathbone Screwfix Select

    Yes, I meant 'notches' as indicated by the mention of the protection plates. Thanks for the clarification.
     
  15. Lectrician

    Lectrician Screwfix Select

    The holes do need to be 50mm above ceiling.
     
  16. unphased

    unphased Screwfix Select

    ...and 50mm below a floor
     
  17. Sparks.

    Sparks. Member

    Which is all very well unless you only have a 45mm total void space, ceilings between open beams for example :)
     
  18. If that is the case, you then fit safe plates or similar pieces of metal to protect the cables.
     
  19. Sparks.

    Sparks. Member

    Above AND below ?
     
  20. unphased

    unphased Screwfix Select

    Yes, that's the point I am making. If you have a beam that is only 100mm deep and drill a hole through the middle, chances are you won't have the 50mm minimum distance. You can count the thickness of the floor and the thickness of the ceiling to add to the depth but most diagrams explaining this seem to show just the beam. I would not advocate drilling through a beam of 100mm depth or less, it would be best to find a different route for the cable.
     

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