How to Buy a Pane of Glass

Measure the opening where the pane will be mounted. Allow 1/16 inch between the glass and the edge of the rabbet on all sides of the pane. A small gap between the glass and the edges of the frame allows for natural expansion and contraction that occurs with seasonal changes in temperature.

Determine the type and thickness of glass required. Older, single-glazed windows commonly use either single-strength (1/16th-inch thick) or double-strength (1/8-inch thick) glass. Newer, energy-efficient windows use a variety of thermal coated, double-glazed or a combination of specialty glass. In addition to these, windows or cabinet panes designed for placement below waist level are usually glazed with tempered safety glass. Laminated glass, two or more panes of glass sandwiched over a clear laminate, is another commonly used form of safety glass.

Contact a glass vendor with your measurements and glass specifications. In most instances, a local glass shop carries standard window glass in large sheets and will be able to cut a pane to size for you immediately. Tempered, laminated or specialty glass usually requires a special order that may take days or weeks to fabricate and ship from the manufacturer.