Damp proof membrane (liquid) and screeding advice

Hey everyone

This is a nice Sunday topic I'm needing advice on

I need to get my kitchen and diner covered with liquid damp proof on the concrete. The plan is then to screed the top.

I am planning to get a few quotes but was wondering if I could get some pointers from people in the know. Maybe let me know some questions I need to ask, what should it cost roughly, or anything else please

I've seen a couple of YouTube videos on them so it looks fairly straightforward but still, pointers from tradesmen here, or others who have had it done would be great.

Many thanks