Glossary

Annealed Glass

Raw glass used as a glazing product. Further processing is required to transform annealed glass into safety glass.

Apron

A piece of horizontal sash or window trim applied against the wall immediately below the stool; serves to conceal the joint made by the sash of window frame sill and the plaster on interior finish surface.

Astragal

An interior moulding (molding) attached to one of a pair of doors or sash in order to prevent swinging through; also used with sliding doors to insure tighter fitting where the doors meet; also a small semi-circular molding or bead encircling a column or post below the capital or cap.

• Flat astragal - a non-rabbeted astragal applied to swing doors; the astagral is applied to the face of the meeting stile of one of the doors.
• Sliding astragal - an astragal so worked so as to cover the meeting joint of sliding doors.
• T-astragal - an astragal, T-like in shape, which is rabbeted to the approximate thickness of the swinging door.

Awning Window

A projecting window, hinged at the top, opening up and out like an awning.

Balance Shoe

Part attached to bottom of balance that attaches balance to sash. A bar or pin on the sash fits in a "slot" in the shoe.

Balance Spring

A device for counterbalancing a sliding sash, generally associated with a double-hung window, so that it can be held open at a position. See Sash Balance

Bay Window

Composed of three or more individual windows, generally with the side or flanker units at 45E or 30E angles to the wall of the structure.

Blind Stop

A sash or window frame member applied to the exterior vertical edge of the side and head jamb in order to serve as a stop for the top sash and to form with the brick moulding and/or casing a rabbet for the storm sash, screens, blinds and shutters.