Get a builder to check your house

 

For most Australians, our homes are a significant financial investment. Home is where you spend a lot of your time, so make time for regular home inspections and maintenance.

No house can be classified as a cyclone-proof house. However, if you understand the effect of strong winds and plan ahead to maintain and protect your house, you can reduce the likelihood of cyclone damage.

If you have a friend or relative in the construction industry, ask them for their help or advice about how. Ideally, arrange for a licensed builder to check your building and identify ways you can increase the structural security of your home to withstand high winds, during storms, and cyclones. Ask your builder to check for rust, loose fixings, and rotten timber and termite attack.

If your house survived a recent cyclone, a building inspection will determine if any damages were incurred that might make you more vulnerable to the next one. Engage a qualified practitioner such as a building certifier, structural engineer, architect or builder to inspect your house if you have doubts about the structural integrity of your house. 

As part of your cyclone preparedness, arrange for a builder to assess whether the structural design meets the Queensland Building Code Appendix 4 design standard. The roof is the most vulnerable part of the house because it has to withstand strong uplift forces. Current building codes stipulate improved interior tie-down standards for improved structural strength.

Key components to check for wear and tear are:

  • Roof
  • Gable ends walls
  • Doors and windows
  • Garage doors
  • Water ingress areas
  • House attachments, and
  • Outdoor objects and equipment.

 

Researchers at the Cyclone Testing Station, James Cook University - Townsville, found that the most common types of cyclone damage to Australian houses were:

  • Damage due to failure of rusted fasteners, connector plates, roof battens, and other components
  • Damage caused by failure of rotten timbers
  • Garage doors being blown in or out
  • Roofs being blown away in whole or in part
  • Collapse of unreinforced masonry walls
  • Damage to inadequately built housing in exposed locations such as hills and sea frontages
  • Flying debris breaking doors and windows, resulting in further damage from water leakage and strong winds
  • Doors and windows blown open due to inadequate fixing to walls or inadequate locks and door sets
  • Damage to ceilings and walls due to water ingress through the roof, doors, windows, vents, etc.
  • Failure of attachments such as guttering, fascias and eaves, and
  • Damage caused by falling trees.

 

They concluded that 'a house requires regular maintenance and protection to reduce the damaging effect of strong winds that develop during a tropical cyclone'.

James Cook University and its partner organisations have developed a comprehensive aHomeowner's Guide - Cyclones… is your house ready?

You can download this document and print pages 14 to 16 of this report so that your builder carryout a Cyclone Readiness Inspection.

In tropical and subtropical climates, houses deteriorate over time because of exposure to sun, rain, and winds. To avoid home deterioration and costly repairs, schedule regular inspections and maintenance.

Was your home built before or after 1981? Building standards improved at that time to ensure that homes are built to withstand expected cyclonic winds. The Building Code of Australia now requires importance level 2 structures (i.e. houses) to be designed according to the wind loading standard AA/NZS 1170.2, which equates to nearly 70m/s referenced at 10m height in flat, open terrain for the cyclonic regions of North Queensland.

If you live along the 50 km wide coastal zone classified as Region C (Bundaberg and north), your house should be designed to resist a Category 5 cyclone with higher wind speeds of nominally 317 km/hr. To avoid wind damage, insist on quality design and construction using materials and fixings designed and tested in accordance with the Building Code of Australia and relevant standards.

Houses built on hill sides, especially on slopes facing the sea and at the tops of hills, are subjected to speed-up of winds over steep topography and should be designed according to AS/NZA 1170.2 and AS4055, which detail current wind load design standards. Houses on flat, unobstructed terrain, for example the edge of a large field, playing field or golf course, are also affected by stronger winds. 

Following Tropical Cyclone Larry (March 20, 2006), James Cook University Cyclone Testing Station survey teams assess damage to buildings and estimated the peak wind speeds were less than the 70m/s, which is the region's design wind speed. . The majority of damage was to houses built prior to the Queensland Building Code Appendix 4 in the 1980s. Contemporary houses that met current structural standards performed well and withstood wind gusts.

Australia is segregated into different wind regions - Cyclone Region A, B, C, and D. The bulk of Australia is zoned region A with most state capitals falling within this zone, followed by Region B (Brisbane). The cyclone area region C runs from 25 degrees south following the coast northward around to 20 degrees south in Western Australia. From that point in WA to 25 degrees south in WA forms the highest cyclone rated region - region D. Scientists believe that climate change and increased ocean temperatures could lead to tropical cyclones crossing the coast and affecting regions south of Region C, even south-east Queensland.