Hi-Tuff cable under paving

Discussion in 'Electricians' Talk' started by seneca2, Jul 29, 2010.

  1. seneca2

    seneca2 New Member

    Hi all,
    I'm thinking of using Hi-Tuff for some garden lighting, the lights will be GU10 (with led lamps)sunk into the paving stones and I don't see a problem? All the cables will be below fixed paving stones therefore will be more than 50mm below surface and protected by the paving. The joint boxes will be acessible through the lamp holes. It will all be rcd protected although not really necessary.
    Any comments anyone?
  2. J.P.

    J.P. New Member

    Super stuff Sen..cannot see any reg breaches whatsoever M8.
  3. J.P.

    J.P. New Member

    To recapitulate..

    1..The cable 50mm plus below bottom of paving slab is well protected physically, and RCD protected to boot, commonsense says this is ok (Red Book not consulted because I don't have one)

    2..The only thing is..is there any risk of water ingress into the ''pots''?..ie is it possible after heavy rain that the pots fill up with water?
  4. fooman

    fooman New Member

    what pots you on about JP ?

    flower pots ??
  5. J.P.

    J.P. New Member

    No Foo..the pots the lights fit in M8. Flipping heck..:)
  6. seneca2

    seneca2 New Member

    I have given that some thought JP but I will be using waterproof boxes with stuffing glands, the lights are ip66 so fully sealed and i'll make the bottom of the hole somewhat deeper than the lamp so hopefully water will drain into the soil below.
  7. J.P.

    J.P. New Member

    Nice one Sen..job done properly, thats what it is all about at the end of the day.
  8. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    (Red Book not consulted because I don't have one)

    . . .Your giving advice on apublic DIY forum JP, without a regs book.

    Shame on you!
  9. J.P.

    J.P. New Member

  10. J.P.

    J.P. New Member

    Well I thought I would say that I don't possess the book but the commonsense factor comes into play Sparky..:) I mean Sens deployment is virtually bullet proof M8..cant see that stuff being written in the regs etc.
  11. Removed 4

    Removed 4 New Member

    Sen: don't attempt to terminate the Hi-tuff cable directly to each fitting - and <u>certainly don't have</u> <u>joints</u> <u>below the paving stones.</u> Run the Hi-tuff to a series of discreetly located above-ground IP66 boxes, then use Arctic flex in flexible conduit under the slabs from there to the fittings. One flex per fitting - i.e., Don't 'loop' from one fitting to another.

    There isn't a need for 'armouring' of cables if other adequate protective measures are used (e.g. slabs) but there is a need to guard against water penetration.....

    Lucia x
  12. J.P.

    J.P. New Member

  13. seneca2

    seneca2 New Member

    Many thanks for your advice Lucia, i'm pleased to hear someone else say that no other cable protection is necessary. However, terminating is somewhat more of a problem! I was thinking Wiska boxes or similar, located below the slabs next to each light, the customer is adamant that she doesn't want connection boxes on show, these lights will be beside two brick walls so there won't be any shrubbery etc. to hide the boxes behind.
  14. propper spark

    propper spark Member

    There isn't a need for 'armouring' of cables if other adequate protective measures are used (e.g. slabs)

    Is this written anywhere as I'd be interested if this is a personal view, a common sense approach or does actually meet the regs. I&#146;m not criticising your suggestion but it&#146;s a common problem if you do garden lighting a lot. I can not see how you could possible terminate armoured at such fittings. Very few cables actually give mechanical protection and sometimes lights on driveway and open spaces can&#146;t have junction boxes near by.
  15. seneca2

    seneca2 New Member

    I am interested in what you're saying proper spark, I must admit i've not seen it written anywhere, i'm just using a 'common sense' approach. Regs. say we need to provide additional mechanical protection and run cables in prescribed zones if less than 50mm below the surface, this will be taken care of by the thickness of the slabs and the layer of roadstone below. As you suggest, swa isn't an option due to it's bulk and awkardness, so i'm thinking Hi-Tuff with the small Wiska boxes and stuffing glands will be ok, provided I can keep them as high as possible down the hole so that they don't lay in any water that collects down there. Although I have done quite a few garden lighting jobs this my first 'lights below ground' job so all help much appreciated.
  16. Removed 4

    Removed 4 New Member

    so there won't be any shrubbery etc. to hide the boxes behind.

    In that case, Sen: Fair enough - u/g joints aren't the ideal method - but if that's what the lady wants (she wouldn't get that from me, though) that's what she'll have to have have.

    But getting back to your main point: Hi-tuff (non- armoured but nonetheless pretty tough) is OK under permanent paving - as is any water-resistant cable/flex -there's clearly no possibility of mechanical damage here.

    Lucia x
  17. ChubbyPhaseWire

    ChubbyPhaseWire New Member

    Hi Sen

    Take a look at

    522.8.10 ;)
  18. Removed 4

    Removed 4 New Member

    Hi Chubby Fatface,

    When were you last 'on the tools', dear? You're certainly handy for spouting 'Regs' - which is how you "earn" your living - but Seneca has to earn his way by being practical and solving real, non-text-book issues.

    Your 522.8.10 Regulation goes on about cable damage by 'reasonably forseeable disturbance of the ground':

    This is a proposed paved area, so it's hardly likely that there'd be any distubance of the ground, is it?

    The main issue here is protection against water ingress to underground joints.

  19. Adam Amp

    Adam Amp New Member

    The 50mm rule does not apply to buried cables in the ground outside. The 50mm rule applies to inside cables buried in walls etc.
  20. seneca2

    seneca2 New Member

    The 50mm rule does not apply to buried cables in the ground outside. The 50mm rule applies to inside cables buried in walls etc.
    Adam, is that written somewhere? if so, I can't remember seeing it, hence my question.
    Lucia, thanks again for your input on this one.

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