Depends what addy you're using, a lot of tubbed gear doesn't need priming first but you shouldn't be using ready mixed in wet areas or with tiles outside the dimensions that are acceptable for tubbed adhesive. You will be best off using powdered cement based adhesive for all tiling and following the priming instructions on the adhesive bag, if you follow the manufacturers recommendation you will be covered if there is a problem with the adhesive.
Do I need to tank around the shower area or primer all the room.there having full height around shower area then drop down to half height.the plaster finished today and I'm going Saturday..
