electrical conduit for wiring

[ban-all-sheds]

25 mmOval conduit will squeeze into the round adapter if you wanted it too

Better to use deformable adapters, like the MK 56462.

 

[SimonH2]

Question : Can I run 2 x T&E in one conduit, so that I don't have to chase as much out the wall?

Yes. It's just a little harder to work on one cable with the other already in place.

Will 2 x T&E fit into a 20mm oval AND 20mm round conduit? I would like to know the answer to this.

I use 25mm oval for 2x2.5mm² T&Es. For AV & network stuff I use 32mm which is (I think) the widest oval they do.
You can always put 2x16mm ovals in - these will fit neatly into 20mm grommets.

How far should the conduit be inserted into the back box and through the grommet? Or is no grommet needed if the conduit is used?

Everyone has their own approach, and for a professional it will be influenced by the economics of the time needed.
The most common technique I've seen is to run the white conduit to within about 1/2" of the box, then dog-leg the cable to fit through the grommet in the box. It's the quick and simple way, but makes future work harder.
If the conduit is small enough, you fit the end into a grommet in the box - this won't work with 25mm oval though as most boxes only have 20mm knockouts.
When I learned from Dad, it was all hacksaw and file. Now I have a nibbler (like this) that makes quick work of enlarging a hole so the oval fits in without distorting it.

And then I carefully de-burr and radius the inside of the conduit end and leave it just flush with the inside edge of the back box.

This is the experts way of wiring behind skirting boards.

I inherited Dad's tools for this.

• A long thin chisel made from what looks like a bit of 1/4" (ish) round bar with a slight bend so it sticks out from the wall far enough to be able to hit one end while the other end goes down the back of the skirting.
• A drill with a sleeve and home-made universal joint that will go down the back of the skirting and drill through the board if it's butted close to the wall.

I don't have to ease the skirtings out at all - though in this house they tend to fall off if you so much as look at them (60s house, wooden wedges dried out and loose).

 

[cwhaley]

I don't have to ease the skirtings out at all - though in this house they tend to fall off if you so much as look at them (60s house, wooden wedges dried out and loose).

One of my first posts on here was regarding this very task. I've been questioned and laughed at for doing it this way, but I like it so much I've fitted skirting to three rooms now using the twisted plug method.

I know silicones are strong, but I enjoy creating the wedges with an axe and getting a firm, secure fixing.

 

[ban-all-sheds]

Because you never contribute anything that is of use.

That would not appear to be the case.

Only a few months ago I posted about a problem where I found metal conduit in the wall with old cable that was deteriorated. You, as well as one or two others tried to make me believe I needed a new ****ing rewire for all the lighting in the place, costing thousands. Sure enough with the help of my spark mate we re-chased a few cables, earthed the boxes, and I could close up and decorate.

You needed to replace all of that old and desperately dangerous cable.

If your "sparky mate" did a quick bodge which did not involve such a replacement then he was neither a sparky nor a mate.

You are just here to try and keep people ignorant, and keep sparkies in work.

Wrong.

You DELIBERATELY don't even write proper english to make what you write unintelligible from a laypersons perspective.

Got any examples?

You need reminding it's a DIY forum and this is a DIY electrics sub forum, people come here to learn

It would be nice if that were always the case.

But it isn't. Some people come here expecting others to do things which they need to be doing themselves. And some refuse to learn when they find out that they don't want what they are being told to be true.

not to have regulations barked at them.

Got any examples?

The soonest possible opportunity you tell someone to go and pay a professional person to do it, whatever they may be doing no matter how small, I've seen you do it repeatedly.

What you will have seen me "do repeatedly" is to advise people who are not sufficiently competent to get an electrician. Electrics are unlike other forms of DIY - if you mess up some joinery, or decorating, or gardening for example, you won't kill yourself or others with doors that don't fit properly, or paint with runs in it, or a dead rose bush.

DIY electrical work must be done to the same standards as a professional would do.

What you will also have seen me "do repeatedly" is to tell people that getting an electrician is one choice, and that the other is to actually learn the things they need to know to be able to do the work themselves, often accompanied by links to learning materials. As in "people come here to learn".

I think you think you know it all, and there's nobody on here that can match your knowledge of electrics, you're wrong.

I don't think that at all - there are lots of people here who know more than I.

Not only that, the way you project yourself makes me resent having to talk to you at all.

I don't "project" myself in any "way" which should cause resentment.

So that's my problem with you. I have the courtesy to actually answer your question honestly and clearly, like you never do to me. So now I've been clear can you stop posting in my thread, because I didn't come here for a fight, I want to get on.

You do not have the right to declare who may or may not post here.

 

[ban-all-sheds]

I just need to know if there is anything I've done here which will void building regulations

What about Regulation 12?

Did you apply for Building Regulations approval before starting this work?

because I will be having it signed off once completed and the connections will be made to the C/U by a sparky.

Well - in the spirit of you coming here to learn, I shall inform you that it does not work like that. An electrician may not "sign off" work done by somebody else.

Either you notify the work in advance, and gain agreement from the council about how you will comply with Part P, or you use a registered electrician or you use the services of a registered 3rd-party certifier, but they too must be found in advance.

 

[HawkEye244]

Yes. It's just a little harder to work on one cable with the other already in place.

I use 25mm oval for 2x2.5mm² T&Es. For AV & network stuff I use 32mm which is (I think) the widest oval they do.
You can always put 2x16mm ovals in - these will fit neatly into 20mm grommets.

Everyone has their own approach, and for a professional it will be influenced by the economics of the time needed.
The most common technique I've seen is to run the white conduit to within about 1/2" of the box, then dog-leg the cable to fit through the grommet in the box. It's the quick and simple way, but makes future work harder.
If the conduit is small enough, you fit the end into a grommet in the box - this won't work with 25mm oval though as most boxes only have 20mm knockouts.
When I learned from Dad, it was all hacksaw and file. Now I have a nibbler (like this) that makes quick work of enlarging a hole so the oval fits in without distorting it.

And then I carefully de-burr and radius the inside of the conduit end and leave it just flush with the inside edge of the back box.


I inherited Dad's tools for this.

• A long thin chisel made from what looks like a bit of 1/4" (ish) round bar with a slight bend so it sticks out from the wall far enough to be able to hit one end while the other end goes down the back of the skirting.
• A drill with a sleeve and home-made universal joint that will go down the back of the skirting and drill through the board if it's butted close to the wall.

I don't have to ease the skirtings out at all - though in this house they tend to fall off if you so much as look at them (60s house, wooden wedges dried out and loose).

Went to the stores looking for 16mm, 20 & 25mm oval to test them all. Ended up buying what I thought was 2 x 16mm in 2 metres lengths and 2 x 20mm in 2 metres lengths. Couldn't find 25mm oval anywhere. Came home realising I bought 4 x 20mm oval in 2 metre lengths ;(

Thanks for the tips, really appreciated. I'll have a go feeding a length of conduit through all 3 back boxes and then snipping them off inside the box and then feeding the cable through like a newb. I'll be on the look out for that tool. Having a look on screwfix, stock 25mm conduit but in multi packs.



I wasted about 3 hours today, 1 hour trying to rechase the cable, 2 hours going to the shops.


What to use instead of bonding plaster? It is only sold in 25kg bags and I need nothing like that amount. Anyone any help on this?


I picked up a smaller 15kg bag of multifinish at least.


Does conduit need to sit flat against the wall? Can it sit on edge ??

 

[HawkEye244]

That would not appear to be the case.



You needed to replace all of that old and desperately dangerous cable.

If your "sparky mate" did a quick bodge which did not involve such a replacement then he was neither a sparky nor a mate.



Wrong.



Got any examples?



It would be nice if that were always the case.

But it isn't. Some people come here expecting others to do things which they need to be doing themselves. And some refuse to learn when they find out that they don't want what they are being told to be true.



Got any examples?



What you will have seen me "do repeatedly" is to advise people who are not sufficiently competent to get an electrician. Electrics are unlike other forms of DIY - if you mess up some joinery, or decorating, or gardening for example, you won't kill yourself or others with doors that don't fit properly, or paint with runs in it, or a dead rose bush.

DIY electrical work must be done to the same standards as a professional would do.

What you will also have seen me "do repeatedly" is to tell people that getting an electrician is one choice, and that the other is to actually learn the things they need to know to be able to do the work themselves, often accompanied by links to learning materials. As in "people come here to learn".



I don't think that at all - there are lots of people here who know more than I.



I don't "project" myself in any "way" which should cause resentment.



You do not have the right to declare who may or may not post here.

What about Regulation 12?

Did you apply for Building Regulations approval before starting this work?



Well - in the spirit of you coming here to learn, I shall inform you that it does not work like that. An electrician may not "sign off" work done by somebody else.

Either you notify the work in advance, and gain agreement from the council about how you will comply with Part P, or you use a registered electrician or you use the services of a registered 3rd-party certifier, but they too must be found in advance.

OH thank you so much banallsheds for gracing me with this valuable insight. I really couldn't have done any of this without you. Without your your input there really is no forum. You are a becon of good hope. You are a becon of good fortune. Always graceful, tactful and mindful of others, you grace all that come upon you with a wealth of knowedgle and insight. Long live banallsheds, in triumph and in glory. Forever and ever. Amen.



























































































sarcasm off/

 

[ban-all-sheds]

OK - sarcasm off.

Any chance now of intelligence and rationality on?

You said I should remember that people come here to learn, and you asked a question about whether what you are doing contravenes the Building Regulations.

I answered that question, but you then behaved as if you didn't actually want it answered, so why bother coming here to ask?

 

[333rocky333]

Better to use deformable adapters, like the MK 56462.

Im surprised they do not make something like these with a thread and bush

 

[Iggifer]

@SimonH2 A cone cutter is also a beautiful tool for enlarging holes quickly. It will obviously keep the hole round but I don't see that as an issue. I got a set of 3 on amazon for about £10 purely for abusing metal with and kept the small one for PVC - they're still sharp a year or so later

 

[sparkwright]

If it's any reassurance, you will get two 2.5mm2 t+e cables through a 20mm oval conduit or a 20mm round conduit.

Always use conduit or capping, because putting cables directly in plaster only causes problems in the future if any damaged cables need repairing or replacing, or alterations are made.

 

[JohnW2]

If it's any reassurance, you will get two 2.5mm2 t+e cables through a 20mm oval conduit or a 20mm round conduit.

It's certainly possible, but I must say that I have had serious struggles at times. It's not so bad if one feeds both into the conduit together, but if one puts one in and then tries to put in a second, my experience is that any lack of perfect straightness in either of the cables can make it very difficult. I wonder what is the experience of others?

Always use conduit or capping, because putting cables directly in plaster only causes problems in the future if any damaged cables need repairing or replacing, or alterations are made.

That's certainly true if the cable(s) is/are in (adequate) conduit, but I'm not sure that capping would make life much easier, would it?

Kind Regards, John

 

[Edddd]

If it's any reassurance, you will get two 2.5mm2 t+e cables through a 20mm oval conduit or a 20mm round conduit.

Can you not just strip the sheath back to where the cable enters the conduit and feed it through as singles? As long as the conduit is continuous into the box.

 

[ban-all-sheds]

Im surprised they do not make something like these with a thread and bush

Or make more boxes with oval knockouts.

 

[mwatsonxx]

Don't waste money on adapters, use 20mm oval and cut a 45° chamfer on both sides of the conduit at the entry point. Use one 20mm per 2.5T&E.