R607.2

Section R607.2 is titled 'Materials' and covers the requirements for the construction of hollow glass block units. The requirement for partial evacuation, minimum face thickness, surface treatment of areas which will be in contact with mortar, and the disallowance of the use of reclaimed units is established. The purpose of this section is to prevent structural failure, reduce thermal energy transfer, and reduce the likelyhood of glass exploding outwards in the event of breakage.

The model shows a new hollow glass block unit which has been partially evacuated, faces that are 3/16" thick or greater, and is coated with polyvinyl butyral.