We're having a house built and the builder has run into a problem with the crown molding. We have a large open great room that opens into the kitchen. The problem is that the kitchen is normal 9' flat ceilings and the great room vaults to the upper level of the home. The builder installed crown molding but says it is impossible to join the molding in the two rooms due to the difference in ceiling angles. Therefore, it's unfinished. Does anyone have any advice on this subject?