latest regs and other general issues

[adrian55]

hello, i am just about to completely rewire a refurbished house. i have done the same to several houses in the distant past. i have just read Scaddon's 'Electrical Wiring for Domestic Installers' and expected it to be full of 'you must do this ', 'dont do that' etc but was surprised that it was not. Someone mentioned to me recently that sockets have to be 450mm up from the floor, and switches 1200 up. I dont want sockets half-way up my walls, is this a regulation? does it perhaps only apply to new-build?
Specifically, i need to run some cables across joists: so i know that, if they are in a notch, they must be protected by earthed metal conduit, so i intend to drill holes at the centre of the 7" joists. Do i need to support the cables in between the joists or just drop the cable down to the plasterboard ceiling (fixed to the bottom of the joists)?
Finally, i am intending to run cables in hollow skirting (Pendoc or similar), but i will be running central heating pipes within the same skirting (pipes will be above, cables at the bottom). Is this against regs?
Thanks for any help.

 

[telectrix]

1.that height for sockets and switches is a building reg, for new builds. on a rewire it;s recommended that they are fitted at a no worse height than previously. the socket height at 450mm is common sense, saves bending low with a 76 year old back like mine. the 1200 for switches is stupid. fit for dwarfs and under 7s kids to mess with,t he recommended height for CUs is also in there, sensible for normal peeps to reach without crawling or climbing.

cables in notches need a steel plate on top of them. these are available from wholesalers. they have teeth to fix to the joists .then just drop down vertically as require. the joists themselves are considered adequate cable support.

as long as the skirting is a dedicated cable trunking (and pipework) fixture OK. should have a note attached to the CU so everybody and their dogs know it. cables and water pipes need to be separated from each other by a minimum of 1"

 

[adrian55]

1.that height for sockets and switches is a building reg, for new builds. on a rewire it;s recommended that they are fitted at a no worse height than previously. the socket height at 450mm is common sense, saves bending low with a 76 year old back like mine. the 1200 for switches is stupid. fit for dwarfs and under 7s kids to mess with,t he recommended height for CUs is also in there, sensible for normal peeps to reach without crawling or climbing.

cables in notches need a steel plate on top of them. these are available from wholesalers. they have teeth to fix to the joists .then just drop down vertically as require. the joists themselves are considered adequate cable support.

as long as the skirting is a dedicated cable trunking (and pipework) fixture OK. should have a note attached to the CU so everybody and their dogs know it. cables and water pipes need to be separated from each other by a minimum of 1"

thank you very much for your reply, i can see the reason for higher sockets, i think i'll compromise with somewhere in between; maybe the light switch height is for disabled wheelchair access. I intend to fit the CU pretty close to the ceiling, but access should be unimpeded, hope that's ok.
Re cables across joists, Scaddon's book says that , if run in notches, they should be in an 'earth metal covering'; it sounds a bit of a fiddle to earth the conduit, so i was going to run the cables through holes at the mid point of the joists, and was wondering if they need to be supported in between the joists.
Re skirting, my other option was to use standard timber skirting (the "tall" stuff) but space it off the wall (with further timber) to create an enclosure and drill holes in the top for venting: would this not be accepptable?

 

[Avo Mk8]

Re skirting, my other option was to use standard timber skirting (the "tall" stuff) but space it off the wall (with further timber) to create an enclosure and drill holes in the top for venting: would this not be accepptable?

As I inderstand it you are not permitted to run cables behind traditional wood skirting boards. Using trunking specifically designed as skirting is the one exception. There is no automatic prescribed zone at floor level, like there is at the ceiling.

Personally I think making something up to be 'trunking', when it looks to all the world like a timber skirting board, is not in the spirit of the regulations and guidance, and could be an accident waiting to happen for future occupants or tradesmen if a long nail or screw were driven in

 

[adrian55]

As I inderstand it you are not permitted to run cables behind traditional wood skirting boards. Using trunking specifically designed as skirting is the one exception. There is no automatic prescribed zone at floor level, like there is at the ceiling.

Personally I think making something up to be 'trunking', when it looks to all the world like a timber skirting board, is not in the spirit of the regulations and guidance, and could be an accident waiting to happen for future occupants or tradesmen if a long nail or screw were driven in

thanks for that, so i intend to use this TK Ply Pipe Boxing - https://www.pendockdirect.co.uk/pipe-boxing/tk-ply-range which says it is a pipework enclosure but doesn't mention cables. However, it does look like it is an enclosure (which is why i was considering "making up" my own enclosure). I could run the cables in PVC trunking within the Pendock boxing, would that be OK? Do you have the actual wording of the regs which might prevent this?

 

[Avo Mk8]

Do you have the actual wording of the regs which might prevent this?

That is a really good question to ask - I'm afraid I can't answer it as I'm away from home and the book - I'm hoping someone else here can help .

In an attempt to support my conviction this is true, I came across this much earlier series of posts on this forum:

Cable Behind Skirting Boards?

Hi all, just wandering what the view is on running a 2.5mm radial circuit behind a skirting board when it's fully protected by a new 17th ed. RCD protected CU. thanks in advance Neil

www.electriciansforums.net

No doubt you will find others.

You can see the skirting board is not a permitted zone from many many illustrations on the interweb.
But if you fit an accessory on the wall you can obviously cable up to it from below the floor (behind the skirting) and above etc. etc. Right now I'm afraid I don't have any more resources to verify this than you have on the web (all of which is true, obviously!)

At the end of the day, it's your house and you can do as you wish.
I've been told in the past not to run cables horizontally behind the skirting (unless there's an accessory to create a zone). So I've never done it.

I don't mean to sound grumpy, and I apologise for that. You've asked several times about using a product to do something that I don't think is a good idea.

Hopefully someone will come along with some words of wisdom, and a solution that is permitted, like burying the cable more than xmm in the wall, or putting it behind steel capping, or in metal trunking.

 

[adrian55]

That is a really good question to ask - I'm afraid I can't answer it as I'm away from home and the book - I'm hoping someone else here can help .

In an attempt to support my conviction this is true, I came across this much earlier series of posts on this forum:

Cable Behind Skirting Boards?

Hi all, just wandering what the view is on running a 2.5mm radial circuit behind a skirting board when it's fully protected by a new 17th ed. RCD protected CU. thanks in advance Neil

www.electriciansforums.net

No doubt you will find others.

You can see the skirting board is not a permitted zone from many many illustrations on the interweb.
But if you fit an accessory on the wall you can obviously cable up to it from below the floor (behind the skirting) and above etc. etc. Right now I'm afraid I don't have any more resources to verify this than you have on the web (all of which is true, obviously!)

At the end of the day, it's your house and you can do as you wish.
I've been told in the past not to run cables horizontally behind the skirting (unless there's an accessory to create a zone). So I've never done it.

I don't mean to sound grumpy, and I apologise for that. You've asked several times about using a product to do something that I don't think is a good idea.

Hopefully someone will come along with some words of wisdom, and a solution that is permitted, like burying the cable more than xmm in the wall, or putting it behind steel capping, or in metal trunking.

thank you very much for your perfectly non-grumpy reply....i have done much searching on the web and all the questions (including the one you link to) seem to be asking 'can you run cables horizontally behind a normal timber skirting board (i.e. buried in the plaster)' and the correct and obvious answer is no. What i want to do is site them within a bespoke hollow skirting (Pendock) made from formed plywood. Whilst Pendock is described as a pipework enclosure, i think it pretty obvious that it will carry services, so i will do it but i might use metal protection for the cables.
There are all sorts of skirtings with small hollow cavities designed for cables on the market, but i would not use them as they look too much like skirting, and hence liable to be treated like it (nailing through etc).