WINDOWS Magazine Summer 2017 | Page 38

WINDOWS | TECHNICAL AWA TECHNICAL COMMITTEE REPORT A VISIT TO THE TOWNSVILLE CYCLONE TESTING STATION 01 In August this year, the AWA Technical Committee visited the Cyclone Testing Station at James Cook University, Townsville, to learn more about how windows and doors perform in severe weather events. RUSSELL HARRIS Technical Manager, Australian Window Association F or over 30 years, the Cyclone Testing Station (CTS) has been at the forefront of damage investigations after cyclones and other severe wind events with the aim of understanding which building products and systems performed well and identifying areas for improvement in building regulations and standards. Post-cyclone investigations conducted by the CTS, data from the insurance industry and accounts from building occupants affected by cyclones frequently show that water ingress and damage from wind-borne debris impact represents the majority of total damage. The consequences of this damage does not necessarily result in structural damage to the property, though in many cases the home is rendered unliveable for some time while the necessary repairs to carpets, furniture and internal building elements are made. This is further compounded by the wide-spread nature of large storms causing available resources to be stretched to capacity leading to substantial repair delays. For more information, please forward your enquiry to [email protected] 36 Summer 2017 Cyclone Debbie, which crossed the coast on 28 March, 2017, as a category-four system, caused widespread damage to buildings in the area between Bowen and Mackay - the most severe damage occurred in and around the communities of Bowen, Proserpine, Airlie Beach and Hamilton Island. Subsequent flooding affected communities as far as the Whitsundays to the northern parts of New South Wales. Over 72,000 Queenslanders requested assistance. As at June 28, insurers had received more than 58,000 claims stretching from North Queensland to northern New South Wales, with a total value of $988 million. More than 80 per cent of claims were for damage to home and home contents. International catastrophe insurance data firm, PERILS, estimates losses in the property insurance market related to the storm at $1.4 billion. Interestingly, it is apparent from the CTS investigations that not all windows or doors leak the same way when exposed to severe weather. Observations made during and after cyclones, as well as home occupant accounts, indicate that even when exposed to similar conditions, some windows seem to allow copious amounts of water in while others leaked much less and just seem to ‘spit’ water. Windows observed to fail quite dramatically presumably have the same (or similar) Water Pressure Ratings as those that perform better - which indicates that the ability of a window to resist static water pressures, as prescribed by AS 2047, is not necessarily a good indicator of its ability to resist real world wind driven rain events. Research and development within the window and door industry has typically pursued design innovation and development around compliance with current standards that require windows and doors to meet water ratings determined in accordance with AS 4420.1 using a static water