At Three Little Pigs Lab, Western researchers break buildings to save them from hurricanes
How do you beat a hurricane?
You could start by creating one of your own.
As Hurricane Irma lashes the northern Caribbean with 295 km/h winds, a group of Western University engineers are replicating high-wind conditions to learn how to build structures that can withstand the worst windstorms.
The research happens at what's officially called the Insurance Research Lab for Better Homes. Those who work there call it the Three Little Pigs research lab (think Big Bad Wolf). A tall steel building placed among the aircraft hangars near London's airport, the research facility is big enough to accommodate a typical two-storey building.
To recreate hurricane-force winds in the lab, the researchers use a complicated system of fans that simulate the same suction forces that can peel roofs off buildings during severe storms.
It's where lead researcher and engineer Greg Kopp and his students build typical structures, then try to break them using the hurricane-simulating fans.
"Ultimately we can take it up to the point where the roof fails," he said. "And we can understand how strong it is and develop models to help engineers make it stronger and more efficient."
The test lab is different than a wind tunnel, which simulates what happens when wind hits a building exterior. With hundreds of pressure sensors placed beneath roof panels and inside walls, Kopp's lab gathers information on how the building responds to those forces.
The data is shared with the insurance industry and companies that make building products. On the day CBC London came to visit, Kopp's team was testing how wind affects a typical light industrial building with steel roof panels.
Though only a few minutes long, the test was enough to "pop" the building's panels — not to the point of breaking — but enough to lift them slightly and pinpoint possible weak points.
Kopp said keeping intact the building's skin — the siding, sheathing and roofing — is essential during wind storms.
For example if one four-by-eight foot roof panel is torn away, the building is likely to be a write-off due to the volume of water that will pour through the opening. Also, a significant percentage of deaths and injuries during windstorms are caused by pieces of buildings becoming missiles.
Often it's simple changes to construction, such as the type of nails used, that can determine whether or not a building is reduced to rubble or stands through the storm.
"It might be as low as five per cent higher construction costs to save the whole structure," he said.
Metal hurricane straps are one example of a simple upgrade that can make even a humble wood-frame house less likely to blow over in high winds.
The clips are small metal braces with screw holes. They're used to connect wood components that would typically be joined by nails. A rafter clip that holds a roof truss to the top off a wall can make the roof structure 40 per cent stronger.
"We call it like a seat belt for your house," said Kopp. "This is not high-tech."
Rafter clips costs a few dollars each and are available at most building centres. But sometimes to save time and money, builders stick to a traditional nails-only approach.
In Ontario's Dufferin County, where it's tornadoes that pose a threat, the municipality paid builders to install hurricane straps.
It's that kind of approach Kopp says is needed to prevent widespread devastation.
"The first time I was on a Florida beach was in a hurricane," he said. "When you're there and you see the destruction, it's moving because people are affected. People's livelihoods are taken away, their homes are taken away. As an engineer, we want to make sure that doesn't happen. That's what motivates us."
ABOUT THE AUTHOR
