Wiring in sheathed cable

[Jackie]

I have to put in a 20A washing machine point. I have a spare 20A circuit on the fuse board. Problem is that I have to run a cable from the fuse board, through an intermediate room and finally to the socket in a second room. The easiest way for the cable to pass through the intermediate room is above the ceiling panels through the wooden beams supporting the next floor.

The other alternative would be to cut a slot in the concrete floor and run conduit through that which I would like to avoid if possible.

My question is this: Is there any form of three core sheathed cable that I could use rather than a much larger diameter gaine. This would minimise the size of the hole to be drilled through the beams. These support beams are quite chunky but I would like to minimise any weakening effect of the holes. Do the regs allow me to do this? I should add that there is some really heavy duty 3 core sheathed cable in the house already, up in the grenier in fact..............John in 79