Brisbane homes aren’t built to cyclone standards but here’s what to do

Brisbane’s homes might not be built to cyclone standards but industry experts say they’ll hold.

As Cyclone Alfred barrels towards South East Queensland in what’s set to be one of the biggest storm events of the decade, experts say the real threat to properties – even old postwar shacks – isn’t collapsing walls but what will fly through the air.

Brisbane’s homes are not built for cyclones but the big issue is debris.Credit: Albert Perez/Getty Images

Airborne trampolines torpedoing into the living room window, and internal flooding, have been tipped to cause the most destruction. And the best thing you can do? Clean up the yard and stay away from external glass.

Geoff Boughton, senior cyclone engineer at James Cook University’s Cyclone Testing Centre, says while Brisbane homes don’t meet the same structural standards as their North Queensland counterparts, they’re still built to handle wind speeds up to 160km/h.

“But debris is the big one. They won’t survive a garden shed being hurled at them,” he said.

“In Townsville and in the tropics, homes are better designed to cope with debris being slammed into them. And that’s an essential difference between a house built for cyclones and one that isn’t.

“The windows are a bit thicker and the pressure they are designed to cope with is also higher.

“So with Cyclone Alfred, glass will be the big problem. And the more you’ve got, the more risk you have, regardless of the age of the building.”

Boughton said the nation’s building codes were categorised into regions based on their susceptibility to cyclonic winds – which in turn influenced construction standards.

Brisbane falls within Region B, which is characterised by lower wind speeds, with homes needing to withstand wind speeds of up to 160km/h, while homes north of Bundaberg are classified as Wind Region C and must be designed to withstand winds of up to 250km/h, which the Bureau of Meteorology classifies as a mid-category four.

A business with taped windows in central Brisbane.Credit: Dan Peled

In Region C, the National Construction Code (NCC) mandates that glazed assemblies in external walls comply with AS 2047, which sets performance requirements for windows and doors, including resistance to debris impact.

“In older places the glazing tends to be float glass and it breaks into much bigger pieces, and that can be more dangerous … if you’ve got louvres all the way around the house, that can also present a big problem for people sheltering behind them,” he said.

So what’s your best bet for weathering the storm? Boughton says stay away from the glass and hunker down in a small room. And for those living in apartments, he advises setting up shop in the bathroom.

“Close the windows and close your internal doors. Make sure the pressure is trapped inside the building. If you’re in a small room where the walls are close together, you’ll be much safer … If you can’t find a small room, try and bunker down in the corner of a hallway,” Boughton said.

“If you’re in an apartment, go into a bathroom – they are often internal, and because they are internal they usually don’t waste glass glazing on a bathroom.

“No matter what, avoid standing in front of glass – just don’t dice with it. If wind is slamming into the front of the building, the inside can also blow up a bit like a balloon, so it’s pushing outwards on all the other windows and it threatens the roof.

“The other big thing is: don’t be tempted to stand in front of the window and mop up the water coming through because water will find its way through anywhere that has a wind gap.”

Master Builders Queensland general manager for building services and licensing Tony Mitchell adds that while South East Queensland’s homes might not have the glass thickness standards required north of Bundaberg, nothing short of a cyclone shelter could withstand an onslaught from major debris.

Cyclones do not usually head this far south.Credit: Getty Images

“In the north they still expect glass to break. Buildings are designed to offset that risk,” he said.

“Even if you laminate safety glass, debris can still shatter it, and that’s why cyclone evacuation centres have protective shutters.”

Mitchell said Brisbane homes in general were as tough as nails, with post-1980 builds particularly better at withstanding increased pressure. As for apartments, he said they were a whole other animal.

“When you have a tower, they are built to withstand different pressures, so I wouldn’t be concerned,” he said.

What he is concerned about is Brisbane residents not taking Cyclone Alfred seriously.

“A lot of people are doing the right thing, but this morning I could still see construction material up against the side of some people’s houses and trampolines propped up against the wall, ready to take off,” he said.

“Our homes are fantastic, and even the older ones have withstood the test of time. But people not cleaning up their yards is where the danger is going to be.”