Detecting a window leak is a lot easier said than done. Unless you are seeing visible dripping during a storm, you are unlikely to “catch them in the act.” If you suspect leakage, look for staining around the corners of window sills after a storm. Look for signs of any possible paint bubbling. The drywall may be brittle and chalky in areas where moisture sat recently. If there is a noticeable leak during adverse weather, call a window installer to double check caulking and the window’s fit. Other reasons for window leaks could be voids in the sealer and wooden window frames coming loose from brick houses.