Housing in cyclone-prone areas should be inspected before the cyclone season so owners can strengthen their properties, James Cook University’s Cyclone Testing Station (CTS) has recommended.

Following an investigation into the March 20 Townsville tornado, university researchers found that although the thunderstorm and tornado caused severe damage to housing and commercial properties, it should have produced negligible structural damage to buildings constructed to current standards.

About 400 houses were reported damaged and CTS found about 20 houses and 12 commercial buildings suffered significant damage.

The windstorm brought peak gusts of 160-200kmh. Buildings constructed before the 1980s were the worst affected.

The technical report recommends that reconstruction and repairs be carried out to the latest standards and that building owners check for hidden damage such as where batten nails may have been pulled out or loosened, weakening the roof.

“This partial loss of resilience has been observed following events such as Cyclone Yasi, Cyclone Larry and Cyclone Vance,” the report notes.

Regular inspection of structural elements, including in the roof space, should be carried out to look for signs of deterioration such as corrosion and rot, it says.

Rebuilding or upgrading of older housing needs to consider the load path from roofing to foundations, as windstorms will find the weakest part of the house.

The report says domestic and commercial roller doors should be designed and installed to strengthen them against windstorms.

Roller doors remain an issue in windstorm areas due to internal damage caused when they blow in. Large doors on commercial buildings can damage the building structure when they buckle under wind pressure.