- Q.We often encounter rot at
the ends of window jambs and exterior casings that abut
sloping wood sills. What is the best way to detail this
connection?
A.Rot is a common problem on
exterior window trim, especially brick molding. Not only is the
trim exposed to rain and snow, but moisture from the interior
often escapes between the window and the rough opening. This
moisture condenses on the molding and rots it from the back.
Brick molding should be back-primed before installation. Seal
the ends of jambs and window casing with paint or varnish
before installation. You could also set the ends into a bead of
long-lasting caulk to keep the joint from trapping
moisture.