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Burying cable- how can gas pipe run across?

Discussion in 'Electrics UK' started by RRRRRR, 16 Mar 2010.

  1. RRRRRR

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    Hi- I'm burying mains cables in a brick wall, before a nice Gas Safe man runs a new gas pipe to a cooker. Am I going to cause problems here, as I believe gas pipes must not be nearer than 25mm to circuits, and the pipe will be running across my vertical cable runs? Is there a way around this for the regs. such as the cable being in plastic tubing in the wall for extra insulation, otherwise I'll have to dig really deep channels? Thanks.
     
  2. ban-all-sheds

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    What did you tell the council would be the way you'd comply with the Building Regulations regarding the electrical work?
     
  3. PrenticeBoyofDerry

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    Where installation pipes are not separated by electrical insulating material, at least 25mm away from electricity supply and distribution cable

    Electrical insulating material is best fulfilled by a piece of conduit, such as where a buried cable must cross a gas pipe buried in same wall surface.

    But it is a kitchen and deemed the same as a special location, so as always part p applys as does informing building controls of new electircal work.
     
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  4. ban-all-sheds

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    If the gas pipe is buried in the wall, won't it be the type with a PVC layer on the outside?
     
  5. PrenticeBoyofDerry

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    Sounds like the op is burying the cable in the wall and the gas pipe will run up the outside of this wall at a right angle to the cable.
    Assuming the pipe should be clipped, this could well bring the pipe away form the wall a distance too.
     
  6. ban-all-sheds

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    It does, doesn't it. :oops:

    Sorry.
     
  7. RRRRRR

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    Hi ban-all-sheds. Thanks for getting back. I haven't told them anything yet, as I'm trying to work out what I can and can't do so things don't have to be redesigned after submitting. Not done this before, and a bit confused to be honest. Is it that you do the best you can to meet the regs., but if really not practicable, there's limited flexibility?
     
  8. RRRRRR

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    Sorry to be dim here, but does this mean that if I bury the cables in a wall in plastic piping/conduit near the surface, a gas pipe can then happily run on the outside of the walll at right angles, and the 25mm rule is not relevant as I have plastic/ plaster as insulation?
     
  9. PrenticeBoyofDerry

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    Yes, as then then you have electrical insulation between both cable and pipe.
     
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  10. ban-all-sheds

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    Not an issue, as they won't want detailed designs, just a statement on how you intend to comply.

    You can read all about it here: http://www.diynot.com/wiki/electrics:part-p


    The Building Regs are pretty easy to comply with, as the requirement is very short on specifics.

    The Wiring Regs too, if you want to go that way, won't stop you do anything which you would sensibly want to do.


    Your biggest issue, I suspect, will be your council's attitude to DIY electrics - if they are one of the miscreant ones then you may want to think again about DIYing.

    Or about notifying.... :confused:

    Is this just a refurb, or are you doing an extension?


    Yup.

    Do be aware of the rules on where you can bury cables though....
     
  11. RRRRRR

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    Hi ban-all-sheds again- great name, and thanks for taking the time to send me the very useful links. I'm knocking through a kitchen wall into an integral garage, to make a bigger kitchen and partitioned storage room, doing what I can myself where I'm allowed to these days (i.e. nowt). I've tackled high levels of wiring/ plumbing/ building in the past, but It's been a while and I'm having an absolute nightmare trawling through Part P's, new partition insulation targets, ventilation, heating, water and drainage, window area, sock colour etc. etc. working out what the BC's will expect when they turn up, once I've applied. I've just discovered for instance that the partition needs to be thermally insulated, so that's another trawl, as I know you can't cover electric cables with heat insulation materials, yet they need to be in the partition too. I think I need to go somewhere quiet and cry in a manly sort of way.....
     
  12. ban-all-sheds

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    You just have to take account of the thermal insulation when calculating the current carrying capacity of the cables, and adjust their size and/or protective device rating to maintain Ib ≤ In ≤ Iz.
     
  13. RRRRRR

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    You've hit exactly where my problems are cutting in! I can work out the depth of insulation required by the regs. and buy the corresponding depth of wood for the partition, build a DPC and the partition wall with water pipes in it, hang the door, plasterboard one side, skim it, everything by the book/ regs., prior to the electrical work being done by a friendly Part P man (or woman- alright Stan) and then find it's all got to come down because the partition's now too thin to accommodate the required width of insulation now that that Ib ≤ In ≤ Iz thingy's come along, 'cos I didn't know about it!
     
  14. PrenticeBoyofDerry

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    It's cable size that will be effected by calculating thermal insulation factors.
    That will not effect the size of your stud wall.
    If the cable installed is completely surround by thermal insulation, it will effect the current carrying capacity of the cable, so the cable could well need up grading.
     
  15. RRRRRR

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    Hi- thanks for even more info. Can't seem to find this area on the regs. Could a Part P electrician then turn up and wire up for a cooker point and extractor hood, with the insulation in place, or do you know if I'd have to get him to do the wiring in the partition first, then ask the friendly BC man what to do with insulation where the cables run?

    When that part's resolved, do you know if I could do the fiddly bit of feeding/ channelling etc. all the wiring in a kitchen extension (all to Part P regs of course), and just get a friendly Part P man to connect it all up if he's happy with it, so Part P's certified? Or is that unacceptable?
     

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