Just need to clarify what exactly I need; I'm scratch coating the stone & mortar walls in my house before I dot & dab the walls, I was thinking of coating the walls with PVA (1 coat) then a 3:1 mix of sand cement & plastesiser and waterproofer would building sand be suffice for this? And would it be better to add lime? As I'm going to dot & dab over I was thinking the lime might be pointless... So if some one clarify the above it would be great...
