Research Looks at Buildings' Tornado Resistance
A civil engineering professor from Ontario’s Western University, who has been studying the effects of high winds on buildings since 1997, is now saying that research could lead to the development of a standard that considers wind loads from the roof to the foundation.
Greg Kopp, who conducts research using full-scale lab testing and model-scale wind tunnel studies, as well as on-site investigations after severe storms, told Daily Commercial News that he’s aiming to identify methods of improving the resilience in homes and low-rise buildings.
“From an engineering point of view, we would like to be able to predict the risk and mitigate the risk for tornadoes. If we are missing a lot of tornadoes even in unpopulated areas, you are not getting a sense of the true level of risk that you have from these events,” he said.
“A lot of the big tornadoes we have in Canada often occur in outbreaks, more than one tornado. So, identifying those and determining accurate rates becomes an important parameter to understand to determine risk.”
Research so far has pointed to increased use of hurricane straps, better nailing patterns on roofs and improved nail quality. However, the engineers are also looking at hip roofs over gable roofs, trusses over stick building and slanted roofs over flat roofs, according to DCN.
“We believe we can build houses that can withstand 90 to 95 [percent] of tornados that are EF-2 tornadoes or less, for a relatively low cost—for a few hundred dollars up to a thousand dollars per house, so it is not a big cost to do that,” he said.
Though changing the building codes is the ultimate goal, Kopp says he just wants to push builders to incorporate the higher standards on their own.
Current projects the team is working on include focuses on the performance of vinyl siding, for residential walls, and metal roofs and for commercial buildings. This is collaborative research involving State Farm, the Institute for Catastrophic Loss Reduction, the Insurance Institute for Business and Home Safety and the Metal Building Manufacturers Association.
Kopp notes that research on low-rise buildings comes with challenges, particularly with small components such as sheathing, cladding systems, soffits, etc., which often fail during severe storms.