I need to repair my Dad's pond which is a "cement rendering on a brick wall" sort of construction. The bricks are in fairly poor shape behind the render which has come away, due to possibly freeze-thaw, but still pretty much solid enough and will provide a good key to render to. The bricks are fairly damp with no possibility of drying out though, but perhaps this is not a problem
What I would like to know is what preparations should I do to the brickwork before applying the render, and what mix should the render be made up of - any special sand / cement / additives ( e.g some Feb chemical?) to make it stick well and waterproof / impervious to stop it leaking ? Should it be applied as dry or as wet as possible to help make it stick ? The bricks will remain damp behind the render.
Thanks,
Nick