The drywall is water stained directly under the two lower corners of my window. So, I need to figure out where the leak is coming from. What steps should I take?
-The home was built in 1967. The window is on the second story and gets a lot of wind and weather as it is on a gable end.
-I removed the interior trim from the window. I'd like to spray foam the window. Should I wait to determine the cause of the leak or can I go ahead as the leak's origin is invariably on the exterior?
-When I removed the trim at the top of the window I noticed that there were a lot of small bits of pine needles and detritus that had somehow worked their way in. The material appeared to be dry.
-After removing the lower window trim, I noticed that there were a speckles of mold on the drywall-- very few, only a handful. But, obviously water had penetrated.
-The lower storm window sash was open for almost a year. (I just noticed that it was open). The regular lower window sash was closed. Could this be the source of the leak?