Structural lessons for housing from TC Yasi February 2011

Tropical Cyclone Yasi (TC Yasi) made landfall in the early hours of Thursday 3rd February 2011 with the eye passing over the Mission Beach region in northern Queensland. The range of wind speeds across the impacted region was equivalent to 55% to 90% of V500 which is the appropriate design wind speed for housing in this region and is nominally 69 m/s. The Cyclone Testing Station (CTS) undertook a detailed study of the region, (Boughton et al, 2011) and found that across the whole study area, in general, housing that had been properly designed and constructed to the current building regulations performed well, but houses built prior to the 1980s had more significant damage. The CTS study reinforced the need to design the whole low rise building envelope, including cladding, doors, windows, roller doors, eaves lining and skylights to resist the expected ultimate limit states wind forces. It also highlighted the role of dominant openings in realising the internal pressures in buildings and made recommendations for changes to wind specification of roller doors, tiled roofs, and water penetration. This paper presents key finding from the CTS study. Implementation of many of these recommendations has commenced