When folks come into our store, I often get asked what the difference is between tempered and laminate glass. Tempered glass is a type of safety glass processed by controlled thermal or chemical treatments to increase its strength compared with normal glass. Tempering creates balanced internal stresses which cause the glass, when broken, to crumble into small granular chunks instead of splintering into jagged shards. The granular chunks are less likely to cause injury. As a result of its safety and strength, tempered glass is used in a variety of demanding applications, including passenger side windows, shower doors, glass doors and tables.
Laminate glass on the other hand, is a type of safety glass that holds together when shattered. In the event of breaking, it is held in place by an iinterlayer typically of polyvinyl butyral (PVB), between its two layers of glass. The interlayer keeps the layers of glass bonded even when broken, and its high strength prevents the glass from breaking up into large sharp pieces. This produces a characteristic “spider web” cracking pattern when the impact is not enough to completely pierce the glass. Skylight glazing and automobile windshields typically use laminated glass.
For most security doors styles, tempered glass is all that is needed. However, for more open styles like the one pictured, laminate glass might be your best bet for that added security.