- A window sill forms the bottom of the window shell. A window is a cut opening in a wall that a frame and clear material (usually glass) is placed in. Window sills are a strong base that redirects water away from the outside of the window and building. It fits under the side jambs and closes the air opening below the window sash. It can be extended on the outside or inside of a window also to form a shelf.
- Window sills are available as a separate part of a window or are sometimes built directly into the window frame. It depends on the specific window style and materials used in the construction of it. Wood window frames make use of separate window sills that can be fixed or replaced. Windows constructed from aluminum or other materials often have the sills already installed.
- Window sills are manufactured for interior or exterior locations. Interior window sills, that extend to form a ledge, are often called window stools. They can be purchased in different materials including various wood, granite, marble, PVC, blue limestone and slate. An interior window sill can be used as a shelf to place objects on (see photo above) or to alter the décor of the window and room.
- Exterior window sills have to be produced to withstand harsh weather conditions. They are often seen on apartment buildings and provide the resident with an outside area to place objects. These window sills are mainly made from limestone, but are also made from other materials, like various kinds of wood or bricks.
- Window sills require routine maintenance to last. Wooden ones must be inspected for damage on a regular basis. If any problem is found, it should be fixed immediately. Wooden sills should be painted and sealed with caulk or made from special pressure-treated wood. The window sills should be cleaned to keep the seal tight to prevent leaks. Even a small leak from a window can cause a lot of water damage quickly.
