STRUCTURAL GLASS FACADES - USC School of Architecture

“Laminated glass is 50% to 100% as strong (depending on aspect ratio and framing details) as
monolithic glass of the same overall thickness and size when subjected to short duration loads at
room temperatures” (Pilkington 2005, p.3).
Loughran (2003, p.113) discusses the problem of interlayer creep under long duration
loading and in the presence of excessive heat.
Break Pattern: The break pattern is purely a function of the glass material as defined
above.
Spontaneous Breakage: An advantage of laminated glass is that even when a single
ply breaks the other ply will hold the panel together and keep the broken glass from
falling. It is extremely unlikely that both pieces of tempered glass in a laminated unit
would break at the same time, so this strategy effectively addresses the concern of
spontaneous breakage.
Safety: Most codes recognize a laminated glass panel of any glass type; annealed,
heat-strengthened or tempered, or any combination thereof, as safety glass.
Optical Distortion: Two pieces of heat-treated glass laminated into a single unit, each
possessing some level of optical distortion because of the heat-treating process, can
potentially exhibit the additive affects caused by the combined distortion. However, if
laminated panels of annealed glass can be used in lieu of heat-treated glass, sharp,
undistorted reflections can be a desirable result. An outer pane of annealed glass
laminated to a heat-treated inner pane can provide superior optical properties when the
reflective surface is viewed outside.
Size Limitation: The maximum widths of laminate glass can be limited by the width of
available interlayer material or the width capacity of the fabricators laminating
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