"Lawrence Zarb" wrote in message
news:cac52b3098f513f5300872ff277b86ae.52329@mygate .mailgate.org...
I have a 2in perimeter trench around the floor to lay the cable in, and
will fill the trench with concrete once the cable is laid

Then you would be better off using ducting designed for burying in concrete
floors. It would make rewiring much easier at a later date too. Your local
electrical wholesaler should be able to supply it.

Colin Bignell