ICLR: On-site damage assessment finds much of the destruction from the Angus tornado could have been prevented

TORONTO, June 25, 2014 /CNW/ - At approximately 5:20 p.m. June 17, an EF2 tornado tore through Angus, damaging more than 100 homes, many severely. A few hours later, Western University engineering's Storm Damage Assessment Team, supported by the Institute for Catastrophic Loss Reduction (ICLR), was on the ground to work with Environment Canada to assess the tornado damage. The team then worked to map the storm track and document damage to about 100 homes, 10 of which had complete roof failures.

According to Dr. Greg Kopp, leader of the forensic research team, much of the damage in Angus could have been prevented.

"Canadian homes are well built, but roofs continue to be vulnerable to strong wind. With small changes in building practices we can substantially reduce the risk that an EF2 tornado destroys a new home in Canada. Along with doing what the building code requires, we need to invest just a few hundred dollars extra in each home to avoid the kind of structural damage we saw in Angus," says Kopp. "These changes would add much less than 1 percent to the cost of a new home."

Dr. Kopp's lab and field research has found that a few low-cost measures can protect homes from the most severe structural damage. These include use of hurricane straps, metal bands that wrap around trusses and connect to walls. "These cost, perhaps, a dollar apiece and can largely eliminate the risk of roof failures from an EF2 tornado," says Kopp. Other considerations include using longer nails in roof sheathing, like 2.5 inch, rather than the code minimum 2 inch nails, placed every 6 inches apart rather than every 12 inches. "The longer nails and tighter nailing pattern more than doubles the strength of the roof sheathing against uplift forces, and the added costs are minimal," he says.

Dr. Kopp is working with ICLR to discuss emerging wind engineering research with Canadian homebuilders and on proposals that have been made to the National Building Code of Canada. We believe that most damage to homes in Canada from severe wind, basement flooding and other natural hazards is preventable with small changes in home construction practices.

Our efforts to assess and document the tragic and preventable destruction in Angus will hopefully result in improvement in future home construction in regions vulnerable to severe winds.

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Established in 1998 by Canada's property and casualty insurers, ICLR is an independent, not-for-profit research institute based in Toronto and at the University of Western Ontario in London, Canada. ICLR is a centre of excellence for disaster loss prevention research and education. ICLR's research staff is internationally recognized for pioneering work in a number of fields including wind and seismic engineering, atmospheric sciences, water resources engineering and economics. Multi-disciplined research is a foundation for ICLR's work to build communities more resilient to disasters.

SOURCE: Institute for Catastrophic Loss Reduction