Page 3
There are many important questions that a homeowner must address to determine if installing this potential safeguard is the appropriate course of action. Three points to consider before installing a sprinkler system are: Are you sure that someone will be home to turn the sprinklers on in the event of a wildfire? Do you have sufficient water to enable a sprinkler system to operate for two to three hours? Is a means of providing adequate water pressure needed in order to operate the system?
These questions, among others, are discussed in the brochure, “Wildfire Fact Sheet, No.11—Community Fire Safety, Sprinkler Systems.” Some other questions asked are: “Is your home constructed from flammable material such as vinyl weatherboards or timber?” and “Does your home have poorly fitting tiles or metal sheets on the roof?”
To learn more about the tests, Wildfire Fact Sheet No. 11 can be downloaded from the CFS web site,
http://www.cfs.org.au/protect/ factsheets.asp and click on “Sprinkler Systems.”or contact Brian Menadue. Brian has been leading this research effort and he may be reached via e-mail at menadue.brian@cfs.org.au.
How can fire modelers best predict what contributions individual elements may add to the overall risk of structural loss in wildland fires?
To address this question, Justin Leonard and his colleagues at CSIRO Manufacturing and Infrastructure Technology in Australia are developing a computer model to predict the risk of destruction of any specific house in the wildland-urban interface. The Australian standard for risk management, AS/NZS 4360 Risk Management, has defined risk as the “chance of something happening that will have an impact upon objectives”. The standard outlines two main aspects required to define a risk event: impact and susceptibility. These two aspects of the standard are discussed, as well
as how they are linked to a physical-based model.
The bushfire impact can be grouped into three categories: flame, radiation, and ember/debris. Each mode of impact has a unique range of properties. It is the authors’ opinions that the area impacted by flame attacks is the overriding characteristic for consideration. Flame quality or specific flame temperature variations due to differences in cellulose fuel sources did not appear to warrant quantification for this attack mechanism. To study the radiation impact upon the house, the most appropriate method is to use a time/radiation curve. Embers and windborne debris are the most prevalent attack mechanism on houses in Australian bushfires.
When considering how a fire event impacts an urban area (excluding house-to-house transfer) well over 90% of the houses are ignited by ember attack.
The efforts of many investigations into building impact in bushfire events, combined with the information from extensive laboratory fire testing of materials and systems performance of various building elements, led to the database of known bushfire impacts that was used in the model.
The physical-based model can link defined models of bushfire impact with observed building element performances. The model utilizes a spatial calculation format to determine the probability that ignitions will occur, as well as incorporating the known behavior of associated elements around the structure.
“Access Denied: Protection Buildings from Agents of Fire”, a paper presented at the 1st Bushfire CRC Conference in Perth, Austrailia, October 7-9, 2004, summarizes the work. Additional information about the model may be obtained by contacting Justin via e-mail at Justin.Leonard@csiro.au.
Fire Spread by Burning Embers Included in Risk Prediction Model