Balustrades made of glass are a sleek, glamorous alternative to balustrades of more traditional materials, such as wood or stone. Glass balustrades can provide a light, airy feel to balconies, staircases, and even outdoor walkways. Glass balustrade construction must meet relevant code requirements, whether national, regional, or per state or locality. Glass balustrade regulations may pertain to glass thickness, glass strength, or handrails/toprails.
The California Building Code states glass balustrades "shall be constructed of either single fully tempered glass, laminated fully tempered glass or laminated heat-strengthened glass." The relevant Ohio Code uses identical language relative to glass strength. The New York City Building Code states that glass "... in guards and railings, including structural baluster panels and nonstructural fill-in panels, regardless of area or height above a walking surface," require safety glazing materials. Safety glazing materials are elsewhere described as tempered or strengthened glass. Both U.K. and Australian codes require that glass balustrading be constructed of "toughened" glass, known stateside as "tempered" glass.
Many jurisdictions in the U.S. and abroad require a handrail for glass balustrades. Requirements for the city of San Diego, California, state "Glass balusters shall not be installed without a handrail or guardrail attached." U.K. regulations require a handrail at elevations of greater than 600mm. In 2006, the Building Code of Australia was revised to require that any glass balustrade include a toprail. These regulations place the safety of the consumer above the aesthetic sensibilities of the design community. For the sake of safety, moreover, in San Diego, handrails must be constructed with adequate support: "Each handrail or guardrail section shall be supported by a minimum of three glass balusters or otherwise supported so that it remains in place should one baluster panel fail." The relevant U.K. Building Regulation, BS 6180, which governs "balcony railings, [and] balcony balustrades," states "The handrail should be attached to the glass in such a manner that, should the glass panel fracture, the handrail (a) will remain in position; [and] (b) will not fail if the design load is applied across the resulting gap. ..." In both locales, the toprail of a glass baluster must be sturdy enough to remain in place even if the glass panel in the balustrade shatters or falls apart.
The building codes for the states of California and Ohio require that glass in balustrade construction be at least 0.25 inches wide (6.4mm). U.K. regulations appear to be more stringent, requiring balustrade glass to be at least 10mm (about 3/8 inches) wide.