Screed repair

I have a just under a metre of screed to repair, solid concrete floor, it’s 25mm (a patched area was not bonded to concrete)

I’m going to slurry and then a 4/1 sand cement/sbr mix

When you slurry with Portland, should it be left overnight or should I apply the sand/cement mix while it’s still wet and tacky, I see different answers.


Thank you all.

 

Wet and tacky.

 

Thank you,

Ardex have recommended this,

ARDEX DPM 1C direct to the smoother or the concrete.

When cured apply ARDEX R3E and sand blind, allow to cure remove any unbound sand before smoothing with ARDEX K15.