Exterior Trim Descriptions

Windows

• Sills can actually be found on either doors or windows. They are wide, horizontal members at the bottom edge of the opening. Door sills are typically more common, and they slant toward the outside so water can run off and not drift back into the home. Window sills on the exterior of the home do the same thing. These should have a groove cut on the bottom of the sill to prevent water from dripping back under the sill and into the home. The casing is the trim molding installed around a door or window opening.

Doors

• Double doors, such as French doors, that swing open on each side need a special piece of molding that allows one door to strike against the other when the doors are closed. This trim piece is called an astragal, and it installs on only one of the two doors. Doors typically have a thick molding, called a brick molding, that covers any gap in the transition space between the doorjamb and the home’s siding. The small gap between the brick molding and the siding is easier to caulk.

Siding

• Corner boards are the name given to the trim pieces that cover the vertical corner where two sides of the building join together. Another trim board used on siding is an apron, which installs along the bottom edge of siding. Aprons may also be found below the rails on a deck, or beneath a window sill.

Roof

• Home builders install trim boards under the roof overhang, which is called the eave. The very bottom of the roof -- a soffit -- is often covered with plywood or other siding that matches the rest of the house. A frieze is a trim board that covers the horizontal transition between the soffit and the home’s siding.