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]

20mm oval conduit 99% of the time.

 

[littlespark]

I would think oval conduit was invented just for being buried in the wall. You wouldn’t run it surface as you would 20mm round.

Also, you don’t need to chase the wall so deep which could be structurally weakened if you go too far.

 

[HappyHippyDad]

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!

Oval conduit is easier as you don't have to chase out such a deep hole. Having said that, I have never tried round conduit in chases, perhaps it has some advantages that I am unaware of.
I 'think' the oval conduit may have an ever so slightly bigger cross sectional area as well.
CSA of 20mm round conduit is 31.4 sq mm
The CSA of an ellipse (a perfect oval) which has 25mm long side and 16mm short would also be 31.4 sq mm, but oval conduit has sharper corners than an ellipse, meaning slightly more area (I think, just by looking).

Also... The triple blade metabo wall chaser takes out a perfect 25mm to squeeze 25mm oval conduit into

 

[7029 dave]

IMO oval tube is used in domestic situations I always use it. If a client wanted the potential to be able to rewire with minimum disruption and mess I would use 20mm round full conduit system in singles. Only disadvantage with this is its much harder for any alterations not that its impossible. More expensive too

 

[Simon47]

Oval is a lot thinner wall as well. As said, designed to minimise the depth to bury it.
It's fairly easy to flex the oval, for example when you get to the box and need to bend it into the wall a bit to match the holes in the box - I NEVER stop the conduit short and dogleg the cables. Doing that with round would need somewhat more effort to set it.

 

[brianmoooore]

In most cases, I bring the oval conduit a few mm into the box, securing it with a dab of building adhesive if I think there's a chance it might get dislodged by 'other trades'.