The Fenestration and Glazing Industry Alliance (FGIA) has updated a report addressing causes of glass breakage by reducing damage to edges, corners and surfaces.

, “Preventing Glass Breakage During Insulating Glass Unit (IGU) Design, Manufacture, Transport, Installation and Use,” was last updated in 1996 and covers IG design for applied loads, fabrication, storage and transport, installation and usage.

“Glass breakage occurs when the glass stress from an applied load exceeds the glass strength,” says Amy Becker, FGIA’s glass products specialist and staff liaison for the Preventing Glass Breakage Task Group. “Glass strength varies greatly as a result of small scratches or other surface damage, which act as stress concentrators.”

FGIA officials explain that glass is weakened by static fatigue that allows a small and invisible crack, which could resist a short-duration load, to slowly grow when the same load is continuously applied. Snow loads on skylights, book and ornament loads on glass shelves or water pressure in an aquarium are all examples of long-duration loads. Visible fractures can appear hours, days or even months after the load is first applied.