Chicago’s use of fire-rated glazing could be impacted by its recent adoption of the 2018 International Building Code. According to the International Code Council, the last comprehensive overhaul of the Chicago Building Code was in 1949.

According to Diana San Diego, vice president of marketing at Safti First, adopting the 2018 IBC allows Chicago to begin recognizing the two types of fire-rated glass as referenced in chapter 7 of the code: fire-protection (or fire protective) and fire-resistance (or fire resistive). Fire-resistive glass is fire-rated glass that defends against the spread of flames, smoke, and hot gas, and limits the passage of radiant and conductive heat. Fire-protective glass is fire-rated glass that defends against the spread of flames, smoke and hot gas. Fire-resistive is tested as a wall, whereas fire-protective glass’ area is limited to 25% of the wall.

“In addition, the three tables in Section 716 clearly outline how fire-rated glazing is to be marked based on testing and where fire-protection glass and fire-resistance glass are allowed, along with its limitations,” says San Diego. “Moving forward, there should be less confusion among architects, building officials and end users on what type of fire-rated glazing should be used for the application because it is clearly outlined in these tables.”

Chicago’s lawmakers revised section 802.6 “Fire-resistance ratings” of the 2018 IBC to read, “Where approved by the building official, buildings where an automatic sprinkler system installed in accordance with Section 903.3.1.1 or 903.3.1.2 of the Chicago Building Code has been added, and the building is now sprinklered throughout, the required fire-resistance ratings of building elements and materials shall be allowed to meet the requirements of the Chicago Building Code. The building is required to meet the other applicable requirements of the Chicago Building Code.”

The 2018 IBC, like earlier versions of the code, limits the use of fire-protective glazing in fire doors used in exit enclosures and passageways due to radiant heat concerns, even when the building is fully sprinklered. According to San Diego, for these applications, wired glass and ceramics, although rated up to 90 and 180 minutes, respectively, are limited to 100 square inches.

“To exceed 100 square inches, fire-resistance (or fire resistive) glass must be used. It is important to note that these changes are in place to improve safety – and with the advent of fire-resistance (or fire resistive) glass tested to ASTM E-119/UL 263, architects are still able to use glass in these fire-rated spaces without compromising safety,” she says.