In recent years, the Toronto area has seen a number of building guard failures involving falling glass infill panels, in addition to other similar issues that have drawn scrutiny. The Canadian Standards Association (CSA) has worked to address those concerns, and a new related standard is now finally in front of the public eye.

glasshandrailsmallAfter years of collaboration and development, a draft of the new CSA A500 Building Guards standard is available for public review at CSA Group’s website here. The review period will end November 30.

According to the draft scope, the standard “specifies requirements for the materials, design, construction, testing, and performance of building guards.” It continues, “This Standard applies to all building guards required as protective barriers, with or without openings, around openings in floors or at the open sides of stairs, landings, balconies, mezzanines, galleries, raised walkways or other locations to prevent accidental falls from one level to another.”

The standard, however, doesn’t apply to: temporary guards regulated elsewhere by applicable health and safety requirements; guards for resisting impact from vehicles; guards used in Group A (assembly occupancy) and F (industrial occupancy) buildings as set out by the National Building Code (NBC) of Canada; or walls acting as guards.

Valerie Block of Kuraray discussed the standard last week at the Glass Association of North America’s Fall Conference. Block said the standard looks at guards from a material/systems point of view and includes testing similar to the ASTM standard.

She said the standard includes a “full calculation approach” in the design guide portion. All materials that could be used in a railing are included. Other key aspects are limits on deflection of the railing system, and that the standard is “much more comprehensive from the point of view of how you look at systems from a durability and maintenance,” she said. “Not just what the designer goes through, but what happens after the system is installed.”

Earlier this year, Paul Gulletson, project manager at CSA, gave a presentation at the Top Glass Conference in Toronto, providing insight into the new standard. He said the benefit of creating “a harmonized, consistent approach” with A500 “will facilitate work for regulators, reduce uncertainty for designers, make designs more consistent, make installations more reliable and, ultimately, increase public safety.”

Some typical challenges in glass guard designs, Gulletson said, are issues with fasteners, connections to surrounding structures and connections to glass components.

Responsibilities for the new standard fall on designers and fabricators alike, as it includes considerations of materials and components, design requirements, deflection and geometry. He added that glass requirements include references to CGSB 12.20 and ASTM E1300 and apply to all types of glass.

Testing requirements in the standards include procedures, guard load, impact resistance, post breakage retention, anchors and fasteners, as well as on-site and documentation.

Once approved, it will be put forth as a reference document for the NBC.