These are conservative designs assuming the glass is horizontal with maximum snow load.
Detailed engineering design particularly on sloped glazing can often increase the maximum allowable size.
(1) These products are recommended for point-supported canopies.
Laminated glass for use in sloped and overhead glazing can be used monolithically or fabricated into insulating glass units. Insulating glass units typically consist of an outboard lite of heat-strengthened glass that resists accidental damage caused by falling objects, and an inboard laminated glass that captures any fragments. Tempered glass is not normally recommended for the outboard lite as small broken particles can easily slide down the outside of the roof and onto the ground in the event of accidental damage.
Laminated architectural glass can be fabricated using various glass types, including low-e, clear, low-iron, tinted, reflective, patterned or wired glass to achieve desired aesthetics or to improve solar control and thermal performance. Mass pigmented and decorative interlayers can also be use to provide a wide range of effects.
Point-Supported Canopies
Point-supported canopies are commonly used as features at entrances to offices, stores and residential properties. They are defined as overhead glazing where the glass is supported by fasteners that pass through holes in the glass and that cannot be offered in annealed glass due to high stresses. The support structure can be either above or below the glass. This type of design is specifically excluded from ASTM E1300 Standard Practice for Determining the Load Resistance of Glass in Buildings and needs careful, specific engineering design.