Using a gypsum smoothing compound still needs a primer onto the anhydrite screed and the gypsum can take a few days to dry. We use a penetrating primer and then a epoxy primer and have done this for many many years with success with a opc compound.
I put 9mm ply over a anhydrate floor today. Think I preferred doing that than smoothing them. Worth more money too. Good bye shitty subfloor Sent from my iPhone using Tapatalk
