Jane Embury looks at high wind loading.
Last week, Hurricane Laura battered the coast of Louisiana, with wind speeds of up to 150mph.
It was one of the strongest storms to ever hit the US Gulf Coast, killing fourteen people in Louisiana and Texas.
In Haiti, which was earlier badly hit, at least 31 people were reported to have died.
Every year sees named storms hit that part of the world, often with devastating consequences.
It’s likely that global warming is partly to blame for both the frequency and severity of hurricanes and typhoons.
The worst was Katrina in 2005 which 1,800 people died. Some 80% of New Orleans was inundated with water.
The insurance industry calls these events mega catastrophes, and their incidence is increasing.
It’s therefore something that has also impacted on the building sector. From product and system suppliers, to architects, designers and builders.
It’s also an evolving policy debate that involves regulatory bodies and national governments.
That debate properly started in 1992 and Hurricane Andrew. It was the second most powerful Category 5 hurricane to make US landfall during the 20th century.
Andrew badly hit Florida, killing dozens and causing over $30 billion in damage. Until Katrina, Andrew was the costliest Atlantic hurricane in US history.
It led to significant changes in the South Florida Building Codes, with new regulations for debris impact, including windows.
The reason, of course, being that flying glass debris is a potent threat to life.
Also, when glass breaks or a window frame fails, the enormous change in air pressure inside a building can cause structural collapse.
Andrew heralded a new hurricane missile testing regime which changed construction practices and building regulations.
Glass and frame
It also led to new composite glass types, specifically designed to withstand the huge pressures of a hurricane. Also, if struck by flying debris, to retain the window or curtain walling element within its framing system.
Since Andrew and Katrina, the glass and glazing industry has invested significantly to understand the dynamics of high wind loading and blast pressures.
It’s all about developing glass and framing systems to keep the glazed element intact and in its frame.
As we repeatedly remind customers, our systems are tested as one compatible unit. The simple fact is that if the glass or frame fails, both fail.
Our systems mitigate against the threats of fire, extreme weather or terrorist attack. We have systems that can withstand even a lorry bomb – and have independent accreditation and live testing video evidence.
In terms of extreme weather, our large-span systems are in place in various parts of the world. For example, at a highly-sensitive banking data hub in Hong Kong, a typhoon area.
Closer to home, they’re also in place at Ocean Terminal, a mixed retail centre in Edinburgh, in a large span configuration that’s believed to still be one of the largest in the UK.
No doubt US federal authorities, pressed by the insurance industry, will again be looking at tightening building and other regulatory codes.
While the unstoppable force of a hurricane will always cause damage, anything that can be done to lessen its impact should be welcomed.