Mains cable hidden in skirting board?

Discussion in 'Electricians' Talk' started by TGull, Apr 27, 2018.

  1. TGull

    TGull Member

    Afternoon all,

    I have very little understanding about electrics so sorry if this is very basic.

    I live in an old house which will inevitably need rewiring at some point. I'm trying to think of clever ways to keep electrics above ground going forward as I'm installing underfloor heating.

    Some people say do the electrics at the same time as the floor, but I can't afford a fully qualified electrician to do this all at the same time. Pluss, I don't really want the cables down where the water is as it will be a pain to alter.

    Ideally I like the idea of a more 'modular' house so you can change and adapt accordingly rather than having to dig up floor boards and hunt through insulation etc. Instead it would be nice if there was discrete but accessible channeling throughout the house. This would (ideally) allow electricians and the likes of to add new plug sockets etc without the need to uplift things.

    The house has nice solid wood 230 x 25mm skirting. I'm wondering if I can route channels throughout the house and run cables this way. I could then cover over again with 'doors' for access.

    I heard someone say that this wouldn't pass xyz regulation as you aren't allow to have cables running parallel or something!?

    The other thing I was exploring is the idea of having some form of modular ceiling (100mm or so) which will look nice (decorative wood paneling or the likes of) but also can be used to store cables and the likes of. If on the ground floor, this can then feed cables up if needs be... essentially like a 1900's floating ceiling.

    Thoughts welcome as this maybe a no no, but would be interesting to hear any ideas.

    If anyone knows of anything similar, or products then that would be great. Ideally I don't want an office style conduit everywhere. Something decorative is must really.


  2. TGull

    TGull Member

  3. rogerk101

    rogerk101 Well-Known Member

    I restored an old French farmhouse that was build in 1818, and wanted to hide the electrics in as discrete a way as possible. I routed grooves behind the skirting boards and ran my 2.5 mm2 wires in the grooves. I routed an 8mm x 8mm groove for each of the 3 wires (line, neutral and earth) which gave them plenty of space to move out of the way if some idiot decided to drill or screw into the skirting board. I created rings like this around each room, with plenty of recessed double sockets, bringing the house into the 21st century. (Mind you I did this all 27 years ago, so brought it into the 20th century back then.)
    Sadly this would probably give the UK nannies a complete nappy rash in 2018, but I don't plan on selling the house any time in my lifetime, and it's in France where they still seem to allow you to use some notion of common sense.
    The project turned out extremely well, but I guess you should ask yourself if you'll ever be selling or renting the house out. If not, just go for it.
    TGull likes this.
  4. unphased

    unphased Screwfix Select

    In the UK it is not allowed to route cables behind a traditional wooden skirting board. However, if the skirting is purpose made for routing cables within it, then that is allowed. Running cables within it is acceptable. Any purpose made skirting for hiding cables is acceptable made from any material.

    Wiring routes buried in walls are prescribed zones. You are allowed to run cables horizontally or vertically between visible accessory positions on the wall, such as sockets or switches. This does not extend to floor level skirting boards, though, that is one exception. You cannot bury a cable in a wall behind a skirting board, even when the accessories might be that low down (I've seen plenty of houses where that is the case).
    KIAB likes this.
  5. Coloumb

    Coloumb Well-Known Member

    A while back I did wonder about using something like 5mm sheet steel behind the board to run a ring around a ground floor/concrete floor but then thought I would only end up worrying about it/doing it again so left it. Sometimes the problem with being a "diyer" is not really having the confidence to try things like that, I mean it could potentially work really well for a ring.
    TGull likes this.
  6. unphased

    unphased Screwfix Select

    I agree, Col. It would be useful to know why particular Regs. are what they are. Knowing the reason behind them would go a long way towards them being more accepted or understood. That's where I get wound up with them, I wrestle with the reasoning. Does my head in. ;)
    TGull likes this.
  7. Niccolo

    Niccolo New Member

    Agree, there are some other points.
    There are minimum socket heights, you don't have to move original sockets and if a room has sockets at low height you can duplicate this to retain the character of the room.

    Good news about zones is; If the wire is sufficiently deep in the wall it can be out of zone and if you use armored cable you can also go out of zone.
  8. unphased

    unphased Screwfix Select

    That's another bizarre use of Regulations. 50mm is a precise measurement, so, 49mm is wrong. Why 50mm? How was that distance decided it would be 'safe' as a means of burying a cable? Part M of the building Regulations is Law. BS7671 is not. Why was 450mm and 1200mm used as a zone boundary?

    Its a mess, tbh, nobody is prepared to simplify any of it because 'they' all look after their own interests. :p
  9. TGull

    TGull Member

    Very interesting thanks.

    Might sound dense, but how do I know if something can legitimately carry cables. Is it just a case of getting it in writing from the manufacturer so to speak and keep note of it. So if i do have an inspection (no idea what this would be like as I have no intentions of selling any time soon) then I have proof that xyz is an approved product!?

    Can you recommend any sites (simple speak for simple people) to help explore this topic a little further?

    Also do you know of any good decorative companies which may provide this.

    I'm speaking with these guys tomorrow at some point - not sure how much it's going to cost though.
  10. peter palmer

    peter palmer Well-Known Member

    Its these so called experts again. someone must have though long and hard about the 1200mm switch height before deciding they should go at the exact height that 90% of noggins are fitted in stud walls, pain in the ****.
  11. joinerjohn1

    joinerjohn1 Screwfix Select

    It’s a bit like who decided that plaster, cement, sand etc,, had to be sold in 25kg bags. Apparently, there’s nothing in EU law that states this. The government at the time, sent out a civil servant to see what sort of “ reasonable weight” he could pick up and after exhaustive tests/ expenses/ stays in 5* hotels, he concluded that 25kg was all he could manage. ;);)
  12. unphased

    unphased Screwfix Select

    TGull. The point I was trying to make is there is no restriction on how you go about making a skirting board in to a cable trunking. The restriction is burying cables behind it. You could, if you wanted to, make a purpose made fillet to sit on top of the skirting board shaped however you wanted it. This is just one of the many quirks of Regulations, they can never be catch all. You could even raise the skirting board off the floor, say 25mm, and use the gap underneath it to run cables in it, then put a fillet over it to hide them. These cables are then classed as surface mounted. All perfectly acceptable. You could put a small label on the CU advising that some cables are routed along skirting boards and which rooms, and also on the actual board in a discrete location. Just use some imagination.
    DIY womble and TGull like this.
  13. Mr Rusty

    Mr Rusty Well-Known Member

  14. Coloumb

    Coloumb Well-Known Member

  15. TGull

    TGull Member

    Thanks @Mr Rusty for pointing this out... Very good find indeed. I have made note of these.... Made from MDF, can come pre primed, and quite cost effective too.

    So I have heard two different opinions from two different suppliers (no surprise there).

    From speaking with Skirting 4 U, they can make quite large skirting boards. This can have a maximum gap behind them of 19mm by 80mm (due to their manufacturing process, not for legal reasons). This should be sufficient for cabling.... they said that you can put power, ethernet etc behind there all mixed up. It should be fine apparently.

    I then called up this company This isn't skirting board but Cornice mouldings. They said the only regulations you had to worry about was mixing electrical cable with data e.g. you can't have electrics with ethernet / speaker / fibre etc. Instead you need a separate compartment for each type. So essentially only two are needed. Example can be seen in that like above.

    I have to say I'm quite baffled with the these strict regulations which seem to be somewhat weird. I was expecting there to be simple diagrams / guidelines here!?

    That being said, I'm also quite happy that there are options out there. I'm thinking that Cornice mouldings might be better as skirting boards have to deal with doors etc whereas cornice mouldings go around the ceiling pretty much uninterrupted.

    So far I'm thinking that when I rewire my house, I can put all electrics up there and then trench down for lights / power points etc... sound like a good idea? Or am I missing something?
  16. TGull

    TGull Member

    Clever thinking. Would you agree with my point above about it being easier to put up high in cornice mouldings?
  17. Coloumb

    Coloumb Well-Known Member

    I would think such a design could not realistically be qualified as trunking or conduit. One would imagine conduit would need to be some sort of surface mounted tube and trunking posses some sort of lid that can be removed. Of course bs7671 may not say that but it will no doubt refer to the relevant BS for conduit or trunking with which the installation must comply, so unless the proposed design can be shown to comply I would think it would not work with LV cables, as in @Mr Rusty post.

    I totally "get" the reasoning being what @unphased is saying but I would say what he proposes is not really in the "spirit" with the regs.
    TGull likes this.
  18. Coloumb

    Coloumb Well-Known Member

    ELV and LV should never be run with any less than 50mm separation unless separated by some sort of barrier, which I think has to be plastic or pvc, probably so it's non-combustible. There is a BS that the regs refer to.
    TGull likes this.
  19. unphased

    unphased Screwfix Select

    TGull. There is a requirement in the Regulations to keep low voltage cable (230V) separate from things like telephone, data, ethernet and elv (12V) wires. Two reasons, firstly, electrical cables can affect data and voice transmission if in close proximity and secondly the insulation on a 230V cable is designed for that, the lower voltage cable may not be insulated to the same standard. It is quite common in trunking systems to have two or more compartments separated for this very reason, then wires are easily kept separated.

    With respect to Coloumb, the points he makes are valid, however, there is no reason why 'trunking' cannot be manufactured or fabricated from a bespoke material as long as it is functional. I think Skirting 4 U take a practical and realistic view of the situation and it would be in the spirit of the Regulations. There are many 'interpretations' that are used freely within the world of electricity, not least of which is , for example, dual RCD consumer units. It is a matter of being practical and applying commonsense. There are as many interpretations of things as there are electricians. Its a quirky trade if I'm honest and many quirky electricians in it.
    TGull likes this.
  20. unphased

    unphased Screwfix Select

    High cornice mouldings are already within a prescribed wiring zone if they are between 0 mm and 150mm of a ceiling junction. Oddly if you bury wires in that zone there is no need for any visible accessories horizontally. So, in that situation, if you really wanted to, you could chop in and bury cables immediately below a ceiling to a distance of 150mm below it, as you can also do 150mm vertically from a corner of a wall junction. Quite why these zones are considered to be 'safe' to install cables is yet another quirk. I suppose the IET are trying to be reasonable and understand the need to be able to put cables in walls where sometimes there may be no other way, nevertheless, they are still vulnerable to having nails or screws entering them, albeit people are supposed to know not to put nails or screws in certain positions on a wall. Realistically people just don't know and nails and screws are still regularly penetrating cables so its all very idealistic and presumptuous of the IET to think it isn't a problem.

    I think in all honesty these measures are to cater for situations where cables are an 'after thought' and need to be added. Normally you would avoid any situations where you would bury cables in corners of walls, along ceilings or in skirting boards. Wires are best run within the loft space or floor voids and kept to vertical burying in walls just to get to the socket or switch, or horizontally between sockets such as above a kitchen worktop.
    Last edited: May 3, 2018

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