Our builder installed wood double-hung windows on the second floor of our home which are directly above bay's on the first floor. The wood windows (which aren't vinyl clad) have a two-piece sill (ie, a sill & a separate brick molding). We are having problems with water coming in through the sill joint which then leaks on the bay ceiling on the 1st floor. My question: Is that set-up (a two-piece sill window above a bay) a design flaw? Thanks in advance for any input.