New question. Residential house has a ducting running from the one end to the other end (wireway/trunking..whatever you want to call it). All the cables are fed from this ducting via surfix, twin & earth, steel piping and pvc. The come out at 90degree angles to their relative load points.

Hear my thoughts.....inside the ducting is armored, twin & earth, surfix and GP wire. The ducting is not closed. Taking the law in perspective, not what is best practice, is it legal to run the GP wire in the ducting while the entire wireway's cover is no longer available. Before you answer, consider this...open wiring is still legal, not preferable, but legal. Open wiring is classified as two conductors running side by side on porcelain blocks X cm apart and supported at Y cm. The wire in the ducting although not fit on porcelain blocks, is fully supported and protected from mechanical strain and damage??

The question; is the ducting legal with no cover (keep in mind that the house was built 20 years ago, and replacing all the wires would be expensive)?