Window stool over sill pan back dam

The Dow Weathermate Sill Pan I installed sits flat on my window sills except for a back dam around 1/8″ high that’s roughly in the middle of my 5″ deep… The Dow Weathermate Sill Pan I installed sits flat on my window sills except for a back dam around 1/8″ high that’s roughly in the middle of my 5″ deep…Read MoreGreenBuildingAdvisor