waterproofing blocks

Extension with double skin wall, concrete blockwork on outer skin. Side wall of extension couldn't be rendered completely due to restricted access The neighbours have a single extension...and between the walls is an 12" - 18" gap , if that. How can i protect the concrete blocks ? Someone said...

Hi everyone. I'm building a concrete block retaining wall using 140mm x 215mm x 440mm blocks (see model below). The plan is to render the blocks however the return highlighted on the left hand side of the image runs by the boundary fence. I haven't drawn the fence in the model which is why you...