Future Development: Tornado-proofing new houses for less than $1,000

January 29, 2019

The vast majority of new houses in Canada could be inexpensively engineered and built to withstand category EF-2 tornadoes, according to an Ontario engineer and wind-damage expert.
Civil engineering professor Greg Kopp of Western University, who is spearheading the Northern Tornadoes Project with the Faculty of Engineering, is confident a standard can be established that considers wind loads from the foundation to the roof.
Kopp contends that houses can be built to withstand up to 95 per cent of Canadian tornadoes with winds of from 180 to 240 kilometres per hour (category EF-2). The extra costs, he said, could be less than $1,000 per house.
Canada gets an average of 62 verified tornadoes per year. Saskatchewan has the highest per province with about 18 tornadoes, followed by Alberta with an average of 15 then Ontario with an average of 12 tornadoes each year, according to federal government reports. Most occur in the spring and summer, with July being the peak month.
The Northern Tornadoes Project research will build on previous findings on methods to strengthen building durability. These findings include increased use of hurricane straps, better nailing patterns on roofs and improved nail quality through longer nails and nails with more friction, such as HurriQuake nails.
Roofs are the most vulnerable part of a house during a tornado—house is destroyed and debris is sent flying into other structures.
Wind engineers recommend hip roofs over gable roofs, trusses over stick building, and slanted roofs over flat roofs to help withstand tornado-force winds.
Kopp, currently chair of the ASCE 49 Standards Committee Wind Tunnel Testing for Buildings and other Structures and a member of the executive board of the International Association of Wind Engineers, aims to push house builders to incorporate higher tornado-resistant standards.
Tornado-resistant proposals are tested at Western’s expansive Insurance Research Lab for Better Homes.