After I scrape up the vinyl (non asbestos) floor tiles, can I lay ceramic tiles directly on to the remaining glue, using a normal floor tile adhesive mix. Floor is concrete. Thanks.

I did and 9 years on still all good. Did rough up the surface very much though.

I can’t see why not. The glue isn’t going any where soon! Why remove it unless you have to? Levels might be an issue, but just where the floor is at its highest, removing glue is much easier than breaking concrete or screed. As long as you are giving your tiles enough grout, and you’re not going to have a step at an adjoining floor – go for it!

Cheers, I will!

The vinyl tiles are coming off nicely, heating them with an iron to soften the glue. Ace.

What’s an iorn?

As long as the vinyl tiles aren’t laid on a bitumen based adhesive you’ll be fine.

If it’s leaving behind a black residue once removed, then this will need skimming over with a latex based self levelling compound as cement based tile adhesive doesn’t stick to bitumen.

Iron as in the thing you flatten a shirt with. It’s a nice Bosch one, so I’m heating the tiles through a sheet of aluminium foil, do it doesn’t get covered in crap.
It’s also good as you can heat the next one while scraping the first one.
They’re on with glue not bitumen. The bitumen can have asbestos in so just as well.