Round vs oval conduit

[DJ12345]

Hello guys! Just quick question, whats better to be buried inside the wall? Round or oval conduit for easy cable management and replacement? I have seen people using round conduit inside the wall but i am not sure if they are right as i have heard from other people that are oval conduit. Whats your thoughts?

Thank you!

 

[brianmoooore]

Some had rolled edges, but the rest, to the best of my knowledge, came ready fitted with an oval rubber grommet.

 

[7029 dave]

Again I recall some did have a grommet already fitted when you purchased them if they were round grommets that had been squashed I don't know / can't remember

Yes some did have cromets already fitted

 

[Marvo]

I've never even seen oval conduit but I'm not a domestic sparky. How would you bend oval conduit, I'm assuming there's no such thing as an oval spring bender....?? Do you get oval male adaptors and other such fittings? I could see it reducing the depth needed for chasing but I'd imagine at a large trade-off.

 

[littlespark]

You don’t/ can’t bend oval conduit… and I think it was developed just for cable drops in chases as an alternative to capping over the top…. With the benefit of being able to rewire through it (if not too packed with cable)

 

[Marvo]

Ah..okay. When we wire a domestic house in conduit it's continuous PVC tubing between the back boxes so you can pull new wires between two sockets or switches or luminaires at any time in the future. Sounds like you don't use conduit that way. Are you guys using steel oval conduit drops as protection? I though that's what your cable zone rules were there for..??

 

[7029 dave]

Ah..okay. When we wire a domestic house in conduit it's continuous PVC tubing between the back boxes so you can pull new wires between two sockets or switches or luminaires at any time in the future. Sounds like you don't use conduit that way. Are you guys using steel oval conduit drops as protection? I though that's what your cable zone rules were there for..??

In singles no doubt

 

[Marvo]

In singles no doubt

In singles or flat twin+e cable

 

[littlespark]

Oval is really just for drops…. So it’s our twin and earth cables as standard, and then run vertically through the oval conduit to the boxes.

Older houses could still have steel conduit and wired in singles… old imperial sized conduit.

 

[Simon47]

You don’t/ can’t bend oval conduit…

You can, but it's a p.i.t.a. to do.
Tape over one end, fill with sand, apply hot air from gun, and ease it round. The sand stops it just completely flattening, but it still needs patience. I find just heating the outside of the bend, and not doing it in one go (bend, straighten a little, bend, straiten a little, ...) helps as it allows the sand to settle a bit each time - if you are stretching the outside, it means the volume is increasing so need to allow the sand to settle and fill it.
Works bending either way - on the wide or the thin face.
We bother ? In our lounge I had to bend the conduits out of the wall and notch the wall plate - otherwise they'd just but onto the top face of the wall plate. In the hallway I needed a 90° bend from coming out the top of the switch backbox to going outside higher up for the outside light.
I hate not being able to alter the wiring, the amount I had to hack out of the plaster in the lounge was ... annoying.

 

[7029 dave]

You can, but it's a p.i.t.a. to do.
Tape over one end, fill with sand, apply hot air from gun, and ease it round. The sand stops it just completely flattening, but it still needs patience. I find just heating the outside of the bend, and not doing it in one go (bend, straighten a little, bend, straiten a little, ...) helps as it allows the sand to settle a bit each time - if you are stretching the outside, it means the volume is increasing so need to allow the sand to settle and fill it.
Works bending either way - on the wide or the thin face.
We bother ? In our lounge I had to bend the conduits out of the wall and notch the wall plate - otherwise they'd just but onto the top face of the wall plate. In the hallway I needed a 90° bend from coming out the top of the switch backbox to going outside higher up for the outside light.
I hate not being able to alter the wiring, the amount I had to hack out of the plaster in the lounge was ... annoying.

Surely it would have been easier to use 20mm round conduit (pvc) and use a spring

 

[brianmoooore]

I regularly work on houses where 600mm thick internal walls are the norm and 1000mm thick walls not unusual. Door frames tend to be set flush with one side or the other, which leaves the light switches on the non flush side effectively in a short tunnel.
For these situations I use corrugated 20mm round flexible conduit, following the 'safe' zone up from the switch, but from there on , to the ceiling in the room, chased in so far as to be out of the zone.