FGIA Summer Conference Session Reviews Natural Disaster Codes, Test Standards

Participants at the Fenestration and Glazing Industry Alliance 2024 Summer Conference heard about the definitions, measurements, codes and testing standards for several natural disasters though an Intertek-sponsored session, “Natural Disaster Standards and Testing.” Led by Tanya Dolby, engineering manager of engineering services, Intertek, the session covered those aspects of hurricanes, tornadoes, earthquakes and floods.

“I am very passionate about this topic and have been involved in it for many years,” says Dolby. “This [presentation] sheds light on catastrophic events and provides insights into their impact, highlighting strategies that can save lives and protect products.”

Hurricanes

“Building codes have come a long way since Hurricane Andrew in 1992,” says Dolby. “That was a wakeup call for the industry and started the process of establishing standards and codes for hurricane impact.” Hurricanes are measured into five categories with different definitions for different types of damage. “Four and five are considered major hurricanes,” says Dolby. “The types of damage vary by category.”

Florida Building Code, 2023, 8th edition, defines wind zones for hurricanes, says Dolby. Several standards and specifications for hurricane testing exist, including ASTM E1886-19, ASTM E1996-20, ANSI/DASMA 115, CAN/CSA A123.21, and AAMA 506. “Projectiles for impact testing range from a BB to a nine-pound two-by-four,” says Dolby. “These are shot at different distances and speeds.”

Tornadoes

“Unlike hurricanes, tornadoes can strike very suddenly,” says Dolby. “They are unpredictable and therefore dangerous. They can leave communities with very little time to prepare.” Tornadoes are measured using the original Fujita Tornado Damage Scale, on which F5 is the most damaging. But in the Enhanced F Scale for Tornado Damage, there is a set of wind estimates, not measurements, that are based on the damage after a tornado passes. “The EF number is assigned at that time,” says Dolby.

Tornado maps can be reviewed within ASCE/SEI 7-22, Minimum Design Loads and Associated Criteria for Buildings and Other Structures. Two-thirds of the U.S. is considered to be a tornado-prone region. Several tornado standards exist, many of which are available online, including FEMA P-361, FEMA P-320 and ANSI/ICC 500 ICC/NSSA. Tornado codes are in the International Building Code, and the Florida Building Code contains similar content, says Dolby. Within 2020 ICC 500 ICC/NSSA, both tornado missile and hurricane missile specifications are defined. Structural test and missile impact test is also defined.

Earthquakes

The Richter Scale measures earthquakes by using the event’s magnitude, says Dolby, who also mentioned that shake table testing has been conducted recently, which can be customized to simulate seismic activity on a reduced scale model of a building or on a full structure. “It was a full-scale shake table, programmed to simulate historic seismic events. The data from the NHERI Tall Wood Project was published last year, which was programmed to mimic an actual earthquake that had occurred in history.”

Floods

Chapter 5 of ASCE/SEI 7-22 addresses flood loads. Other relevant flood standards include FEMA TB 3-93, NFIP Technical Bulletin 3, and ANSI 2510-2020. NFIP Technical Bulletin 3 shares a practical test for fenestration products. “It is a very simple test to perform,” says Dolby. “The important thing is the vertical depth of the testing chamber.”