I am rerouting wires in a condo. The original construction has every wire running through rigid conduit. It would be much easier for me to use flexible conduit for the reroutes. Are there any limitations to the length of a flex run? Can sections of rigid conduit be interspersed when it is convenient? Is steel flex better than aluminum flex? Please note that the wiring is such that all grounding is through the conduit, not through a separate ground wire. Thanks in advance for your input.

There is no limitation to length, only that there are no more than 360 degrees of bends from one junction box to another.

Also, flex is not suitble as an equipment grounding conductor, such as the rigid conduit, so a green wire of the appropriate size to the circuit must be installed along with the branch wiring..

Steel offers more physical protection than aluminum, aluminum is lighter and easier to work with. Not sure of the cost difference at the moment..

There is even nonmetallic, PVC, flexible conduit to chose from. All the necessary fittings and boxes are available also. May be worth looking at.

I caution you thou, if this condo is attached in any way to another unit, you may not be allowed to do your own wiring, please check with your local building official for the approval, while you are applying for a permit.

Flexible? As in greenfield?

What exactly are you planning on adding or moving?

But what is the easiest way to thread the wire through the flexible conduit? I am trying to get 14AWG through 1/2" flexible pvc conduit for a run of about 17 feet -- can't get the last 3 or 4 feet pushed through!

But what is the easiest way to thread the wire through the flexible conduit? I am trying to get 14AWG through 1/2" flexible pvc conduit for a run of about 17 feet -- can't get the last 3 or 4 feet pushed through! they use nylon or metal snake... or you could drop a pull line in before installation by using a heavy object ( a small metal rod/bolt) and attach a string to it...

Easiest way is to use fishing tape made to pull wires through a conduit. I have had good luck with coat hanger wire on shorter runs. As cheap and easy as PVC is to work with, perhaps cut it and set an ''LB'' at one of the sharper bends.