Hi all. Rendering a newly built house the past week or so. Scudded 2-1. Scratched 4-1 with evoplast waterproofer. Nap finish at 5-1-1/2 with evostik plaz. Scud and scratch went fine but the finish is baffling. Scratch would be wet down the evening before a couple of times and again in the morning wet down 2 r 3 times before applying finish coat. Elevations would be nice and damp. The problem is when we go back screeding there are dry patches and wet/moist areas. Dry patches are about 12-18 inches square and are going "crusty" while other areas are as I said holding well for a float. It's not where the sun/wind are hitting the wall because some parts are in shaded places. We are thinking maybe it's a s**t waterproofer or the sand is dodgy. Anyone ever come across this before. The walls are wet down consistently so it's not because areas are missed when wetting down. Usually only 2 r 3 spots the size of a football on a decent size gable....? Again I stress the walls are wet down consistently well.