There's one reason why I used to love 16mm flex conduit before I had a Hilti... old construction plaster is usually thick enough to take 16mm conduit without touching the bricks. It doesn't really take more than 4 1,5mm2 wires. I once fitted 6, but it was a stright run and I had to use copious amounts of liquid soap.
Briselec, You are absolutely right mate. The Grey stuff is u-PVC (UV-stabilised PVC). The Orange stuff is Chemically resistant PVC. I have never ever seen Orange PVC conduit being painted and I mean there is HEAPS of it used over here, a lot of it by Power Companies. I just read in AS/NZS 3000, it is supposed to be painted if not UV stabilised. You learn something new every day.
