Understanding the specific double hung window parts names is essential for any homeowner contemplating repairs, maintenance, or an eventual replacement. A standard double hung unit consists of two vertically sliding sashes that move up and down within a frame, creating a timeless aesthetic that remains popular across traditional and contemporary architecture. This guide provides a detailed breakdown of the names and functions for each component, allowing you to communicate effectively with contractors and make informed decisions regarding your windows.
The Primary Sash Components
The most active parts of a double hung window are the upper and lower sashes, each responsible for holding the glass and creating the opening. Each sash contains a frame, commonly referred to as the stile and rail configuration, where vertical pieces meet horizontal pieces at the corners. Integrated within the sash channels are essential balance mechanisms, usually hidden springs or weights, that manage the lifting and lowering resistance. These sashes also feature a bottom rail, which is the primary load-bearing edge, and a top rail that connects to the various hardware used for operation.
Key Sash Elements
- Sash Frame: The perimeter structure that holds the glazing.
- Meeting Rail:The horizontal joint where the upper and lower sashes meet.
- Top and Bottom Rails: The horizontal head and foot of the sash frame.
- Sash Balance: The tension system (spring or weight) counteracting the glass weight.
The Frame and Jamb Assembly
Securing the sashes in place is the main window frame, which is typically constructed from wood, vinyl, or aluminum. The vertical portions of this enclosure are known as the jambs, providing the structural support into which the window is installed within the wall. At the very top of the opening sits the head jamb, which forms the lintel and bears the load from the building above. The side jambs create the throat of the window, guiding the sashes as they move vertically, while the sill, or apron, forms the bottom ledge that catches rainwater and provides a surface for installation.
Critical Frame Parts
- Jamb: The vertical legs of the window opening.
- Head Jamb: The top horizontal frame member.
- Sill: The bottom horizontal frame member, also called the apron.
- Jambliner: The interior trim used to finished the jambs and reduce the opening size.
Hardware and Operation Mechanisms
The functionality of a double hung window relies heavily on the hardware positioned on the sashes and frame. The sash lock, often located at the meeting rail, is a critical security and ventilation component that locks the sashes together while allowing for slight airflow. Operators or cranks are used to pivot the window inward for cleaning from the inside, while handles or pulls are grasped to move the sashes. Additionally, tracks or rails guide the sash cords and ensure the vertical movement remains smooth and reliable.
Operational Hardware
- Sash Lock: The device that secures the closed window.
- Operator: The mechanism that allows the window to tilt in for cleaning.
- Sash Cord or Chain: Connects the sash to the balance system hidden in the frame.
- Window Stays: Metal supports that hold the window open at a desired angle.
Glass and Finishing Elements
Glazing holds the glass panes within the sash frame, typically using a glazing compound or putty that hardens to create a waterproof seal. The parting bead is a thin strip placed between the upper and lower sashes to separate the glass panes and prevent them from rattling. Finally, the exterior casing trims the rough opening, covering the gaps between the window frame and the wall to protect against moisture intrusion and enhance the curb appeal.
Glass and Seal Components
- Glazing: The compound securing the glass to the sash.
- Parting Bead: The strip separating the two panes of glass.
- Casing: The finished trim that covers the gap between the frame and the wall.
- Weatherstripping: The material applied to seal air gaps between moving parts.
