The concrete drive at the side of my house slopes towards the house with a fine gap between 'horizontal' concrete and vertical brickwork. I want to put a fine fillet of waterproof mortar over the gap, which will direct rainfall towards a drain. Strength is not important, nor speed of setting, but I am thinking of Everbuild Jetcem Waterproof Rapid Repair Cement. My question is- should I prime ( with water or PVA or SBR ) the 1/2" or so of concrete and brick that the mortar mix is going to sit on ?
