capping nails and galvanised sheathing

Discussion in 'Electricians' Talk' started by boo907, Sep 1, 2005.

  1. boo907

    boo907 New Member

    Any tips for fixing galv sheathing to masonary when capping nails bend and will not hold. Have been having to drill and plug and screw galv to hold it. Also I always fold over 1/2 inch of galv and flatten it and re shape it to protect cables at knockout boxes and ceiling voids. This is time consumming, does any one make plastic end covers to be fitted to sheathing ( similar to grommetts to protect cable ) or sheathing which does not have sharp ends. Or am I the only one who re shapes the galv ?
    Thanks for any response, if you can understand what I mean !
     
  2. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Lo Boo!

    I take it you have tried pre-drilling the edges of the Galv. sheathing before hand and then hammer home the cap-heads in to the masonary/mortar

    I know its a ******* of a job I have a re-wire on the go at the mo (poet and didnt know it!!...:) )and the whole house is built from Engineers brick.

    Anyone else?????
     
  3. You should not really be using metal capping as it HAS to be earthed (remember the rules for accesability of connections).
    When fixing plastic capping i use large head galvo nails into the morter joints at the edge of the capping with the head catching the lip or 2.5 tw&e clips
     
  4. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Have you tried banging the nails in at the brick edge where it meets the mortar ?




    Mr. Handyandy - really
     
  5. boo907

    boo907 New Member

    Hi sifi, I dont pre drill galv as the nails will go through the metal galv ok . I scrounged some 2 inch nails the builder left about and they will go in old mortar bed but eventually bend over last 1/2 inch or so , will hold it but looks *****. Do you bend and reshape ends of galv ?
     
  6. steve CF

    steve CF New Member

    be careful using standard steel nails

    sometimes they can rust under the plaster and after a few months you have horrible brown rust marks showing through the plaster
     
  7. contractor

    contractor Guest

    'galvanised capping HAS to be earthed'


    have I missed something somewhere?

    Surely plastered over conduit in prescribed zones does not need bonding, as it is not extraneous metalwork.Good electricians do not run cable other than in prescribed zones.

    Try drilling and plugging the walls and then use 50mm clout head galvanised nails. Job Done.
    We always fold over the ends of galv. capping, only takes seconds, no problem.
     
  8. boo907

    boo907 New Member

    You should not really be using metal capping as it HAS to be earthed (remember the rules for accesability of connections
    There are no connections beneath the galv , suprisingly the cables run un broken from knockout box to knockout box and switch plate to light points.
    The earthing of metal capping is debateable as it cant really be defined as an extraneous conductive part and cant be contacted either directly or indirectly .
    Personally I do not use plastic capping as it doesnt really offer much protection as opposed to metal.
     
  9. baldelectrician.com

    baldelectrician.com Well-Known Member

    Am I missing something, i havent used capping since around 1992, and haven't missed it

    I use a wall chaser (ferm from S Fix) it cuts a channel and i put the cables in about 1" deep.

    no capping req as cables in safe zones.

    why make life hard for yourself.
     
  10. Ok, You could argue cables dont need any protection when buried in plaster but all good sparks do cover. boo97 the connections i mention are the earth connection to the capping.
    Metal capping must be earthed. It offers fractionally more protection than plastic. As You said, you easily put a nail through to fix it, its even easier when buried and if you clip the live conductor you have now livened up the whole length !
    Lastly, plasterers have mentioned that render doesn't stick to it very well.
     
  11. Bando

    Bando Member

    "I use a wall chaser (ferm from S Fix) it cuts a channel and i put the cables in about 1" deep.

    no capping req as cables in safe zones."

    But doesn't render and plaster have an effect on the cable?
     
  12. Alex G

    Alex G New Member

    Blad,

    Your a rough spark to not use oval conduit or capping, I hate it when cables are just burried in plaster, you can't do anything with them without re chaseing the wall.
     
  13. sinewave

    sinewave Screwfix Select

    Yes render and plaster possibly do effect bare cable sheathing.

    So, to make life easy, especialy if capping to engineering brick use plastic capping within 'pescribed zones' and fix to brick with liquid nails or gripfill!

    Job done, piece of urine, and no risk of eye injury due to metal splinters or flying masonary.

     
  14. Spark69

    Spark69 New Member

    Render and Plaster used to afect cable sheathing when it used to contain lime.

    Surely it's good working practise to cap cables when a wall is to be plastered, if anything to protect them from the plasterer and his sharp trowel. If the wall is dry-lined (dot & dab) then it's ok to just clip them within the zones.

    Not sure about metal capping having to be earthed, it's an interesting point which i'm going to make inquiries about.
     
  15. baldelectrician.com

    baldelectrician.com Well-Known Member

    That's the point of it.

    When they are buried they are out of harms way, usually i use my own plasterer who is good and hasn't hit any cables yet- i usually clip the cables below the surface out of the way

    'Your a rough spark to not use oval conduit or capping'
    maybe the cable REALLY needs a flimsy bit of plastic to protect it from those nasty nails.

    that's the point of permitted cable routes- cables are less likely to come to harm
     
  16. Alex G

    Alex G New Member

    Its not so much the protection of the cable's bald, its the fact if there trapped in plaster - you can't pull any more cable into the box or renew the cable without re channeling.
    For the sake of pennies per drop, why don't you use conduit?
    I think its really so rough not too - but hey who am I to tell you how to do your work, I just know how I am going to carry on doing mine.
     
  17. Twobarrows&asprog

    Twobarrows&asprog New Member

    So, to make life easy, especialy if capping to
    engineering brick use plastic capping within
    'pescribed zones' and fix to brick with liquid nails
    or gripfill!

    Job done, piece of urine, and no risk of eye injury
    due to metal splinters or flying masonary.


    Grip fill ? Liquid nails ? You must have money to throw away :) Try the Dow Corning decorators Caulk, terrific stuff & dirt cheap!
     
  18. ban-all-sheds

    ban-all-sheds New Member

    Where does it say that?
     

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