Technical Information - page 3

Glass should be stored in a dry, clean and cool location where the temperatures are above the dew point. Circulation of dry, cool air is required, especially after periods of high humidity and cyclic temperatures if glass must be stored outdoors, use tarps or plastic coverings to protect if from getting wet and vent periodically to prevent moisture accumulation. Repeated wetting and drying of glass surfaces can result in staining or etching of the glass.

WEEP SYSTEMS
The glazing system must be designed to prevent the accumulation of moisture in the glazing channel for prolonged periods. This applies to dry, wet and lock strip glazing, as well as sloped and structural glazing. HGP recommends 3 weep holes, 3/8" diameter or equivalent, per sill - one at the center point of the span and one each 4" inboard of the unit corners. For door and window wraparound gaskets, provide sufficient weep holes to prevent retention of water at the unit edges.

SETTING BLOCKS

Glass should be set on two identical setting blocks with a Shore A Durometer hardness of 85±5. They should be equidistant from the center line of the glass at the bottom quarter points. Each block should be sized to provide 0.1 " of length per square foot of glass area but not less than 4" of length. The setting block should be 1/16" less than full channel width. The height should provide the recommended -nominal bit and minimum edge clearance for the glass. When a lockstrip gasket glazing system is used, each setting block should be sized to provide 0.4" of length per square foot of glass area but not less than 4" of length The height of the blocks should be recommended by the lockstrip gasket manufacturer.

EDGE AND FACE CLEARANCE, AND BITE

The glazing system must have adequate edge and face clearance to cushion the glass, thermally isolate the glass and framing members, and prevent glass-to metal contact. Adequate bite is required to provide a proper seal against air and water infiltration; however, excessive bite will increase thermal breakage. Refer to chart for proper clearance values.