Oh dear, Im worried - please put my mind at ease
I have a 'regular' block and s&c render house, with a flat roof in the final stages of build. I finally had the windows sealed (rubber between frame and glass and the mastic between the s&c and frame) a few days ago. Todays rain has shown a problem on 14 of the 18 door/window openings - a wet patch at the bottom of the inner reveal (always on one side, just) - see pic. (There is S&C behind the cladding).
I have noticed this previously, but the builder felt it was because the rubber on the windows was missing - obvs, Ill speak with him in the morning. What is most likely to be going on?