Ceiling or floor joists?

[Thisoldheartofmine]

The chap in the flat below us talks about work to his ceiling and his ceiling joists.
We are in a 1900s house divided into 2 flats.
Would there be a set of ceiling joists in his flat underneath us?
Separate from what I would call floor joists.
Or is it common to have 2 sets, ceiling and floor ?

Usually your floor joists are his ceiling joists.

What’s the work?
Adding soundproofing?

He's actually done the work now , I'm not sure exactly what was done.
We're joint freeholders so of course he should at least have kept us in the loop.
I believe he was thinking of taking his ceiling down and was concerned about the condition he'd find his ceiling joists in .
But I think he just did some work on one corner.
I just wanted to check that I wasn't being overly precious about the joists and being annoyed by his attitude and description .
He's selling and will be gone soon . Hopefully.

There is only one set of joists, your floor is on the top of them, his ceiling is on the bottom of them . In rare cases there might be a two sets with a void in between but 99% of the time it’s one.