"F" wrote in message
...
I've got a small cloakroom floor consisting of concrete blocks with an up
to 2" covering of sand and cement. How long do I have to wait before I can
drill and plug it to install a studded partition?

TIA.
Screed is a surface leveller not a structural layer - don't fix to it ...
fix through it to floor below.

Screed should have a week per inch of thickness .... if you want to go
quicker give it a soaking with water (it sets by chemical action not drying)

You can sprinkle the surface with a concrete hardener (easy availability)
give a very hard dust free surface if that is needed)

Rely on the vertical fixing of stud partition for fixing, and just count on
anything to screed as a bonus - but don't rely on it for mechanical fixing.