Impact Tests May Not Be Representative, Team Concludes

The movement toward effective hurricane resistant structures began in earnest with Hurricane Andrew in 1992 – a landmark storm that left 160,000 southern Florida residents homeless, resulted in 40 deaths and produced $25 billion in damages. The building codes at the time, as well as code inspections and disaster preparation were later judged...
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The movement toward effective hurricane resistant structures began in earnest with Hurricane Andrew in 1992 – a landmark storm that left 160,000 southern Florida residents homeless, resulted in 40 deaths and produced $25 billion in damages. The building codes at the time, as well as code inspections and disaster preparation were later judged inadequate. As a result, the Dade County product approval and impact resistance TAS protocols were instituted.

Fast forward to 2017 and Hurricane Irma. Although the monstrous storm resulted in 134 deaths and $65 billion in damages, it produced less damage in newer homes built to the post-Andrew codes than in older housing stock. In essence, Irma was evidence that we have learned from and have made great progress since Andrew.

An assessment team from PGT Innovations consisting of Vice President of Product Management, Dean Ruark, and professional engineers Lynn Miller and Robert Beaird, as led by the University of Florida, examined the impact of Hurricane Irma on buildings and infrastructure throughout the state. Their analysis identified weaknesses and strengths in the remaining structures and examined the performance of impact-resistant windows and doors in areas most affected by the storm.

The PGT Innovations team shared their insights and images of destroyed homes with AAMA Southeastern Region Winter Meeting participants. Working with universities and FEMA, the group researched first hand where opportunities exist to make building products even stronger.

There were several key findings. We found that older homes that did not withstand the storm often became a source of WindBorne debris for newer, more sound homes. The homes that took the brunt of this debris experienced significant impacts to their building envelope and fenestration products. We witnessed windows and doors that incurred multiple debris strikes to the glass as well as significant strikes to the framing members. Miami Dade County testing protocols require fenestration to be impacted multiple times on the glass as well as the framing members, however, ASTM E1996 recently removed this requirement and only requires a single strike to the glazing.

“Thus, although we’ve made great progress since Hurricane Andrew, missile speed, size, location and frequency should be reviewed based on the collective findings of universities, FEMA, ASCE, insurers and other industry stakeholders,” the team concluded.

Source: aamanet.org