Plastic capping......whats it purpose?

Discussion in 'Electricians' Talk' started by sparky Si-Fi, Apr 28, 2004.

  1. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    As mentioned on a number of occasions with regard to cables requiring mechancial protection if installed in a wall or partition at less than 50mm outside of 'safe zones.

    Then could someone tell me why is plastic cable capping readily available here and on wholesalers,as it does not prevent the penetration of nails,screws and the like.

    OK cables concelead in a wall or partition installed in verticaly or horizontly runs the width of the accessory do not need mechanical protection,so what we are saying that using the pvc capping we are more than satisfying Regulation 522-06-06.

    feedback please?

  2. scotspark

    scotspark Member

    metal capping dont offer any protection either. i mean you put it up with clip nails so if you drill or nail into the wall the only chance youve got is if you hear it

  3. daz

    daz New Member

    plastic capping is meant only for surface fixing - not hiding behind plaster (in which case it would prove of no use) and is primarily for aesthetic purposes while still allowing some physical protection. others might disagree though ...
  4. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    where would you use it for surface fixing?

    The stuff looks vile!

    Cannot see any of my clients wanting it

  5. Damocles

    Damocles New Member

    Thought the idea was to create a tunnel so you can pull another wire through in the future if you have to, without smashing the wall to pieces
  6. Rabbit Rabbit

    Rabbit Rabbit New Member

    I think Damocles has it in one and it ssort of protects the cables within against plaster. It offers no protection, just like metal capping.

    Daz I have never ever seen plastic nor metal capping used at the surface - I think you are confusing it with box plastics conduit (with or without so called self-adhesive).

    If ya want REAL protection then the ONLY solution is round steel conduit piping - but first do a degree in plumbing! Its been around since the year dot and is still around and it trebles the cost of the installation.
  7. SWA

    SWA New Member

    I always thought plastic and metal capping was just for mechanical protection during the building process, ie plasters trowels etc, when compliance with 522-06-06 cannot be achieved then I think 522-06-07 applies and you need to make use of an earthed steel conduit, as mentioned, neither plastic or steel capping satifies the requirement to prevent nail penetration, with conduit at least you have a good chance of stopping the penetration.
    Cables that are concealed in the plaster without capping etc are not necessarily non compliant, mabye just the spark was responsible for the chasing out and patching, whereas he then could provide care with the patching and satisfy himself of no damage.
    Just my view

  8. Lectrician

    Lectrician Screwfix Select

    plastic, galvanised metal, its upto you, its to protect the cables whilst the plasters plaster the wall, it isnt to protect against penetration ATALL.

    Best to use oval tube, you can remove and reinstall cables easily with this.

    beware on galv capping, where you cut, you expose the metal under the galvanising, this can rust through the plaster work, and leave a stain on your wall. Similarly, ensure you use galv nails.
  9. Rabbit Rabbit

    Rabbit Rabbit New Member

    Some good points Lectrician. I used to use oval all the time, it's MUCH better than plastic or metal capping. As you quite rightly say some sparky in the future will thank you for using oval when he has to draw throgh another or replace the cable. And you can nail sideways into plaster prior to filling up the channel, I HATE shoving in those capping nails!

  10. Lectrician

    Lectrician Screwfix Select

    cheers rabbit, still cant fathom out quite why they produce galv capping? (or even plastic caping:) ) I know its quicker, but it aint a proper job.
  11. The Trician

    The Trician New Member

    The purpose of plastic/galvanised capping is to comply with some absurd regulation in BS7671!

    Don't worry about it, or whether or not its up to the job, just fit it to comply.

    We all know that an SDS masonary drill at full-chat takes no prisoners, but the regs is the regs sadly.

    Steel conduit?

    In a domestic environment?

    You've got to be joking. Today's new houses are not constructed with thick enough walls for a start. And don't you think that the builder & electrical designer/installer would specify it if it was required under BS7671?

    Think about who's pockets we are lining by having to comply with lots of needless regulations.

  12. Lectrician

    Lectrician Screwfix Select

    pvc oval conduit dosnt break the bank, have you seen the damage a plasterers trowl can do a pvc cable clipped to the wall? The oval tube (or capping if you really are trying to save money) is there truly only to protect the cable, you can clip the cable direct if you wanna, but the nails will rust through, and the chances of damaged cable are high.
  13. sparks

    sparks New Member

    Your quite right as usual oval tube is a far better job than capping and with 20mm oval you can get it right inside the assessory box, I've always understool that the capping is there just to protect the cable during construction as we all know it provides no protection against drills, nails or screws etc.While were talking about 1st fix it really annoys me the way builders fit floor and ceiling joists tight to the wall so thats its impossible to run cables behind them, the old builders allways left them off the wall.
  14. Lectrician

    Lectrician Screwfix Select

    And the new timber builds are even worse, you have to calculate where you can drill, and what size hole, how many holes per meter etc.....

    Know what you mean, old houses are the best to re-wire!

    And what do you mean...quite right as usuall.....!
  15. The Trician

    The Trician New Member

    Agree about the fitting of joists.

    But - can anyone explain to me why they believe that oval plastic conduit provides more protection against nails/screws/masonary drills?
    I simply cannot understand the reasoning behind this.

    From experience, an SDS masonary drill will make mincemeat out of any plastic protection, so what's the theory guys?
  16. Lectrician

    Lectrician Screwfix Select

    no one said oval tube provides my protection! Read slower :)
  17. Lectrician

    Lectrician Screwfix Select

  18. tellondon

    tellondon New Member

    I don't think it offers any protection against Nails screws or drills just a plasterers trowel
  19. Lectrician

    Lectrician Screwfix Select

    exactly what was said
  20. tellondon

    tellondon New Member

    This is going along the lines of the post `capping bonding` or what ever it was, i thought we was all clear what the capping/oval tube,metal or plastic was used for?

    It actually doesn't have to be used at all but it does protect the cable from a plasterers trowel and it does keep the cables neatly in a chase but it certainly doesn't offer any sort of mechanical protection plastic or metal

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