Is using Conduit for 2.5mm T&E ok?

[Bobajob11]

Hi everyone, hoping you can help me with my extension.

We have had a 2 storey extension built and its time to fit the electrics.

A good friend who is fully qualified is doing the work and he has allowed me to run the T&E in for the lighting and sockets, he even promised not to rip it all down and start again if I did a good job

The walls are blockwork and will have a plastered finish using dot & dab.

My father-in-law who built the extension has told me to use Conduit (even though the t&e will be chased in)on the 2.5mm t&e as it makes a nice neat job.

I was going to use this: http://www.screwfix.com/p/tower-oval-conduit-16mm-x-2m-white/91802

My question really is, can I run 2 lengths of 2.5mm t&e in one piece of 16mm wide conduit or does it have to be single.

Also for the wall sockets I was just going to finish the conduit a few inches from the back box and a few inches from the ceiling, is that ok? or is their regs on where the conduit finishes if used.

Seems an awful lots of words for 2 questions, so im sorry for rambling and thank you for any help you guys can give.

Cheers, Bob

 

[EFLImpudence]

Yes you can use that.

It doesn't really do anything other than hold the cable and allow the cable to be removed.
If you can, have it protrude above the ceiling and into the back-box.

You will need one for each cable.

 

[Bobajob11]

Thanks for the reply, really appreciate it.

I presume I sill have to get rubber grommets as well for the ends of the conduit.

Thanks again.

 

[OwainDIYer]

You don't need rubber bushes for the end of plastic conduit.

I'd be surprised if you get 2 x 2.5mm t&e down one 16mm oval. You will get it down one 20mm circular conduit, but that may need a bit of wall chasing out not just the plaster depth.

Run the conduit into the back box so it protects the cable from the edge of the box hole.

The conduit can be softened in hot water if you need to manipulate it into place.

 

[Bobajob11]

Thanks for the reply Owain,

Its going straight onto blockwork (has yet to be plastered) so chasing out will not be a problem if I purchase a bigger size.

The thing I was not sure on was if I could run 2 t&e wires down the same conduit run, but you are saying that would be ok correct?

Cheers, Bob

 

[ekmdgrf]

I prefer 20mm round conduit as you can attach it properly to the backbox. Oval just looks a bit crap stuffed into the hole. That said, dry lining boxes don't tend to have 20mm openings and also as they're a bit crap anyway it doesn't matter too much if the conduit looks crap too

 

[Bobajob11]

I have purchased metal back boxes ekmdgrf, will take a look at the 20mm round stuff.

 

[ban-all-sheds]

I prefer 20mm round conduit as you can attach it properly to the backbox. Oval just looks a bit crap stuffed into the hole.

If you get some of these MK Masterseal conduit adapters.

you can fit them over the end of oval conduit as they are squashy.

 

[ban-all-sheds]

The thing I was not sure on was if I could run 2 t&e wires down the same conduit run

Read this and decide:

http://www.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=5365

Although ultimately it isn't what you think that matters, as (presumably) you aren't going to be signing this declaration:

I being the person responsible for the design of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2011 except for the departures, if any, detailed as follows:

your good friend will be.

So as he is a good friend he is the only person on the planet who can tell you if it will be OK to put both cables into the same conduit.

 

[Bobajob11]

Thanks ban all sheds, those will do nicely.

And thank you for the link, I know how you guys feel about people who are not certified doing electrical work and I agree 100%
I have a wife and 2 children to keep safe and I want the job to be spot on, I have helped build the extension and have really enjoyed it and so wanted to be involved in helping with the electrics too.

In saying that though I know my limitations and will leave 95% of the work to him, I am also paying him to inspect any work I do as I would not want somebody spreading plaster on a wall but then paying me to trowel up.

I could phone and ask him but I will end up peeing him off with constant phone calls so I thought I would see if I could learn from here.

Thanks anyway though, Bob

 

[sparkwright]

You will NOT, NOT get two 2.5 mm2 twin and earth cables in a 16 mm oval conduit.

You need at least the next size up.

Don't waste your time getting 20 mm circular conduit - it's not worth the effort of extra chasing.

Capping is more desirable on any new blockwork - as chasing is not required here.

Capping, though wider, is more shallow than most oval conduits, so it's better for the electrician and the plasterer.

As said, make sure the conduit or capping just enters the ceiling void - makes any alteration that bit easier.

Pushing the end of the conduit into the box is not a favourite of mine - unless I am only installing the conduit, and the cable will be put in later.

The neatest way is use a grommet on the box, and, with the cable in the conduit, butt the conduit up to the grommet. You will still be able to pull slack on the cable should you ever need to.

Leave a small, neat loop of slack in the cable above each conduit - just in case.

 

[Bobajob11]

Thanks Sparkwright, What you suggest does make good sense and have ordered 40 meters.

I take its fine to run 2 x 2.5mm t&e in the 25mm wide capping?

Cheers, Bob

 

[ban-all-sheds]

I take its fine to run 2 x 2.5mm t&e in the 25mm wide capping?

If you have a shred of decency you will get a grip and decide who is going to take legal responsibility for the design.

If it is to be you, then you must acquire the necessary competence to make design decisions and be in a position where you can sign the declaration above.

If it is to be your good friend then it must actually be your good friend who answers questions like that, not a group of anonymous strangers on the internet.

What it cannot be, and what nobody who considers himself a good friend of the other should do, is design done by anonymous strangers on the internet and presented to the other in the expectation that he will lie (for that's what it would be) on official documentation and say that he did the design.

So - time to fess up, if only to yourself.

Is there really an electrician involved?

Is he really a good friend of yours?

Are you really going to ask a good friend to falsify documents for you?

 

[Bobajob11]

Do you have some kind of mental issue?

I looked around this forum before posting my question and could tell from your previous posts that you have a severe issue with people attempting to even wire a plug.

You can tell you have a problem by your post count, 47000 reply's ?, wow do you even go to work? are you even an electrician or just someone who sits there with a reg's book so you can lecture others on what is and is not right.

Its electrics, not rocket science, you are not a doctor saving lives, more likely a bitter old man who spends his days criticising others.

I do not lie, period. My knowledge of electrics does not allow me to wire the extension by myself, nor does my skill level, what I can do though is help although that is none of your business anyway.

So please for the good of this forum, Do one and stop being a dick.

 

[ban-all-sheds]

Do you have some kind of mental issue?

No.

Do you have a truth and honesty one?

I looked around this forum before posting my question and could tell from your previous posts that you have a severe issue with people attempting to even wire a plug.

That is a gross distortion of my position on people attempting work which they are not competent to do.

Its electrics, not rocket science,

But it does seem to be beyond your current level of competence.

you are not a doctor saving lives, more likely a bitter old man who spends his days criticising others.

I'm neither of those, and if I criticise people it is because they have done something which deserves criticism.

I do not lie, period.

Good.

Are you expecting your good friend to lie?

So please for the good of this forum, Do one and stop being a dick.

Are you one of those people who gets bent out of shape when you don't get the sort of advice you had decide you should get before you came here?