I was advised to use "BAL ctf3" for a tiling job but the only supplier in my area want,s a kings ransom for it. I was told about this product and spoke to there tech department today. Its tile adhesive called "Keraflex Maxi" and its made by "Mapei". Has anyone used it. I told there tech they were large format tiles going on an old skim of plaster and some would be going direct onto unskimmed water resistant plasterboard, he advised using another of there products called "Primer G". So once again has anyone used it. I was advised to use "BAL APD" for this job originally. I not well up on tiling adhesives so i dont know if these products are any good.