Conduit bends in wall

[sparkwright]

Am I missing something here?

This is just regular twin and earth cable in oval conduit in plaster? With no particular attention to new wiring being pulled through in the future?

To my mind there's no point in using conduit if you can't pull the wire through. You might just as well clip the wire to the wall and plaster over if you don't want to do it properly.

Cobblers.

The main point of oval conduit or capping is to prevent the cable getting damaged from plastering up the chases.

If cable should get damaged in the future, it is certainly very beneficial if conduit has been used as it may be possible to draw a new cable in. Obviously there would be damage where a 90 degree bend is, and sometimes where the conduit meets the box.

Unless the op is determined to have his conduits done in such a way a rewire can be carried out without a damage to the walls, then I think it is reasonable, if not the norm, to simply mitre the oval conduits.

Round conduit which seems to be a minimum of 20 mm nowadays is the best option for a re-wirable conduit system, but depending on the number of cables required, singles may well be required. And if singles are required more round conduit may well be required to run the singles back to a convenient position.

I would say twin and earth cable in mitred oval conduit is absolutely acceptable in a domestic dwelling, with attention to safe zones.

 

[sparkwright]

There's this

http://www.tradeindia.com/fp328804/OVAL-ELBOW.html

but a waste of time really as you won't be able to re-wire the cable.

Since you have indicated you have no plans to re-wire anything, I wouldn't worry too much.

 

[phatboy]

Thanks for all the replies - I didn't expect such a good response!

I will go with oval conduit, and mitre the corner. There are no plans to rewire or to be able to pull cables through later one, so this will be fine.

The rest of the place is wired in round 20mm conduit, in singles, which I thought was a bit unusual!

 

[EFLImpudence]

To my mind there's no point in using conduit if you can't pull the wire through. You might just as well clip the wire to the wall and plaster over if you don't want to do it properly.

Cobblers.

Not cobblers. It's obvious.
Proper conduit has to be installed before running the cables.

The main point of oval conduit or capping is to prevent the cable getting damaged from plastering up the chases.

Plasterers eh.

If cable should get damaged in the future, it is certainly very beneficial if conduit has been used as it may be possible to draw a new cable in. Obviously there would be damage where a 90 degree bend is, and sometimes where the conduit meets the box.

Not acceptable as such, then.

Round conduit which seems to be a minimum of 20 mm nowadays is the best option for a re-wirable conduit system, but depending on the number of cables required, singles may well be required. And if singles are required more round conduit may well be required to run the singles back to a convenient position.

But it must be installed before running the cable.

I would say twin and earth cable in mitred oval conduit is absolutely acceptable in a domestic dwelling, with attention to safe zones.

Of course it is because it doesn't do anything.
Equally acceptable is chased into masonry as in -

To my mind there's no point in using conduit if you can't pull the wire through. You might just as well clip the wire to the wall and plaster over if you don't want to do it properly.

 

[sparkwright]

Round conduit should be installed first before drawing in cables.

But it can't be expected to install oval conduit entirely before running in the cables. Take a typical house rewire, cables emerging from the top of a skirting board to go to a recessed box six inches above.

You can't expect someone to battle running a cable through a piece of oval conduit already fixed to an unplastered wall.

 

[EFLImpudence]

I know.

Oval doesn't count as anything so Detlef's comment was perfectly sensible.

 

[sparkwright]

Thanks for all the replies - I didn't expect such a good response!

I will go with oval conduit, and mitre the corner. There are no plans to rewire or to be able to pull cables through later one, so this will be fine.

The rest of the place is wired in round 20mm conduit, in singles, which I thought was a bit unusual!

20 mm round conduit in singles? Unusual in a house, very common in a flat.

You mention you have used 20 mm oval for your additions. Presumably you have used flat cable as opposed to singles.

You are fine to use flat cable in oval for your alterations. Singles in round conduit is of course desirable, but requires more effort and not essential.

 

[sparkwright]

Oval doesn't count as anything so Detlef's comment was perfectly sensible.

Well, perhaps you are right, but he's missing the point that the oval is primarily used to protect the cable from the old adage - the plasterer's trowel.

And it has to be said if trying to renew a cable through an oval conduit, it's better to damage just the area of wall where the 90 degree bend is. If no conduit at all the whole cable run would have to be chased out, or a nasty crimped joint somewhere.

 

[17thman]

when chasing for conduit horizontally, you must remember that if you have a cavity wall, then it is very difficult to acheive the 1/6th requirement