I have a similar problem in two very different buildings. My steel workshop has 4″ thick concrete block walls for the first metre (fire prevention). I have coated these with 2 coats of Dulux Weathershield plus 3 coats of PVA but the water still soaks through and puddles on the floor. What else should I try? Also, my house is built of 18″ thick granite with the stonework exposed on the outside. It has always been damp with rain soaking through the old mortar. I don’t want to cover the stonework. If I rake and re-point what should I add to the mortar to stop the water ingression, or is there something clear I could just spray on to seal the old mortar? Thanks for your help.