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IBHS Issues Preliminary Damage Report from Hurricane Ike

Roof coverings were the No. 1 point of concern in this storm

The Institute for Business & Home Safety released Sept. 16 its preliminary report from a survey of the damage caused by Hurricane Ike.

Dr. Tim Reinhold, IBHS chief engineer, and researchers from the University of Florida, Texas Tech University, Florida International University, Louisiana State University, and Clemson University spent two days in Texas surveying property damage in Galveston, Houston, and the surrounding areas.

“The damage we have seen from Hurricane Ike drives home the need to establish clear definitions and standards for secondary water protection to achieve the kind of performance we need to keep water out of homes when these storms occur,” said Reinhold. Secondary water protection is the moisture barrier between the roof deck and roof covering.

According to IBHS, although Ike contained a large amount of energy, the storm spread moderately strong winds over a large geographic area rather than very strong winds over a small area. Equipment from the University of Florida and Texas Tech University recorded wind gusts of 116 mph in rural areas about 50 miles northeast of Houston, but lower wind speeds closer to the metropolitan areas. Preliminary observations include:

Raywood

  • Damage to roof sheathing and siding were more prevalent. This type of damage is consistent with what is expected in Category 2 hurricane conditions.
  • A large number of multi-story homes and commercial buildings only put window protection on the first floors, leaving upper stories vulnerable to flying debris.
  • There was a significant amount of damage to commercial roofs.

Houston

  • Damage primarily involved roof coverings rather than sheathing (roof deck), which is consistent with expectations for Category 1 hurricane conditions.
  • Newer shingle roofs, tile roofs, and metal roofs performed well. Older shingle roofs sustained some damage in terms of lost shingles and underlayment.
  • Generally, downtown Houston looked similar to what was seen in Fort Lauderdale, Fla. and Miami following Hurricane Wilma in 2005, although the overall extent of damage appears less.

Galveston

  • Storm surge was the major cause of damage.
  • Older buildings built below current flood elevation requirements suffered the most damage. Buildings that were not elevated experienced major storm-surge damage on lower levels and damage to roof coverings.
  • Newer buildings that were properly elevated according to modern building codes performed well.

“What we have seen in terms of wind damage from Hurricanes Gustav and Ike reinforces the IBHS decision to focus on roofing failures during the first two years of investigation at the Insurance Center for Building Safety Research,” Reinhold said. “Roof coverings were the number one point of concern in this storm.”

This week, IBHS and university researchers will review supplementary data and information, including aerial photographs, in an effort to determine the impact that different variables had on the roof cover damage that has been observed.

Source: Institute for Business & Home Safety

Posted: Tuesday, September 16, 2008 12:00:00 AM. Modified: Tuesday, September 16, 2008 4:11:45 PM.

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