What are the fire ratings of Pittsburgh Corning Glass Block products?
With the exception of all 12 inch by 12 inch sizes-finishing blocks, corner blocks and the DELPHI® pattern block, all glass block sizes 8 inches by 8 inches or less in size have at least a 45 minute fire rating when used as a window assembly within a one hour rated masonry or non-masonry studded walls.
All THICKSET® 90 (thick-faced) and solid glass blocks have fire ratings of up to 90 minutes, and the new THICKSET® 60 glassblocks have fire ratings up to 60 minutes, when used as window assemblies and when permitted by code.
All of our fire rated glass block products along with maximum sizes and dimensions are listed in Underwriters Laboratories' current issue of Fire Resistance Directory - Volume 3 under our classification number R 2556. A listing of our products can also be viewed on Underwriters Laboratories' Website at www.ul.com.
Are there specific details for installing fire rated glass block window assemblies?
The framing, anchoring and installation details are the same as installing any non-fire rated glass block panel and as shown in our published literature. The one distinct difference is that the sealant used at the jamb and head locations must be a fire retardant type sealant.
Also all 90 minute rated glass back window assemblies may only be installed within masonry or concrete walls, may only by framed and anchored with ¼ inch thick steel channels or angles that form channels; and the expansion material within the channels must be doubled (or ¾ inches thick).
Finally our VeriTru® plastic spacers are listed by Underwriters Laboratories under Classification Number R 18572 and can be used to construct fire rated glass block window assemblies.
Click here for Glass Block fire ratings results.
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