Anhydrite screeds need priming but you should only ever use a primer if one is recommended by your chosen adhesive manufacturer or if conditions are dusty. Use a proprietary acrylic tile primer rather than SBR, it’s a waterproofer & could affect adhesion; not worth the risk.
You need a cement based powder adhesive of the correct type for your tiles &, to reiterate, only ever use quality trade tiling materials not cheapo own brand & DIY products.
Richard C
You need a cement based powder adhesive of the correct type for your tiles &, to reiterate, only ever use quality trade tiling materials not cheapo own brand & DIY products.
Richard C