I need to hang something from a single point on a ceiling. The load will
be about 300Kg max, after allowing a suitable safety factor (actual load
closer to 100Kg).

Any ideas or caveats?

I meant to look for a joist tonight in an out of the way location
(probably a cupboard), make a hole in the ceiling there & have a prod
about, as I'm not sure how much variation there is in possible
structure, but the battery's flat in my stud detector, so that'll have
to wait until tomorrow.

FWIW This concerns a flat in the middle storey of a small three storey
block, which was built in the 1970s. I won't have access to the floor
above, as that's obviously someone else's flat.

--
Peter Purr