On 25/03/17 12:03, F wrote:
It looks as though I'm going to have to thread a thin, so very flexible,
cable into the ceiling void from below and then out again a couple of
metres further across. I've used a straightened coat hanger in similar
circumstances before but the current stock won't straighten to the
required distance.

I can't get at it from above, but at least the joists run in the right
direction for me.

So what's the best way to do it?


The classic way is something like the lid from some 15-20mm trunking -
it's rigid enough to poke, but flexible enough to go through holes. Tape
the cable to the end and push.