A Bushfire Attack Level (BAL) Assessment is a statement of your Bushfire Attack Level (BAL) rating in which a certificate and a report are written unique to your development. A Bushfire Attack Level (BAL) report delves into the classification of vegetation and the bushfire risk it poses to your property within a 100 m radius of your development.
A Bushfire Attack Level (BAL) is determined by the amount of heat flux that a structure would be exposed to in the case of a bushfire, and is measured in kW/m2. If your development has been given a Bushfire Attack Level (BAL) rating of BAL-29, this means it is exposed to a moderately high threat from bushfire with sufficient risk of an ember attack and some of burning debris ignited by windborne embers.
BAL-29 is primarily concerned with protection from ember attack and radiant heat greater than 19kW/m² up to and including 29 kW/m². There are compulsory construction requirements determined by the Building Code of Australia and AS3959 to ensure that the building is able to withstand a heat flux of up to 29kW/m2. AS3959 list of bushfire construction requirements for Bushfire Attack Level (BAL) are as following:
- Subfloor supports, including support posts, columns, stumps, piers and poles shall be made from a non-combustible material or Bushfire-resisting timber, which can be found in AS3959.
- Walls of a structure to achieve compliance with a Bushfire Attack Level (BAL) rating of BAL-29 are to be of non-combustible material, or cladded with non-combustible materials or a combination of the materials specified by the AS3959.
- Roof covering shall be made of non-combustible or materials specified by the AS3959 and the underside of roofs are to be sealed to avoid any gaps and threat of ignition through ember attack.
- All unclosed structures such as Verandas, Decks, Steps, Ramps and Landings must be made from a non-combustible material or a bushfire-resisting timber, which can be found in AS 3959.
- All doors and windows must be fully covered by bushfire shutters or screens.
- Door and window frames and all assemblies are to be non-combustible.
- All glazing shall be toughened Grade A safety glass which a minimum thickness of 5 mm.
- Ember guards and mesh screens are to protect all openings vents, weep holes etc.
- Joint openings in all joinery to be kept at a minimum size as specified by the AS3959.
- All water and gas supply pipelines to be made from metal.
These necessary bushfire construction requirements for a Bushfire Attack Level (BAL) rating of BAL-29 are in place to ensure the upmost safety of the property and inhabitants. If you have achieved a Bushfire Attack Level (BAL) of BAL-29 and require extra information, please contact us your BPAD accredited Bushfire Attack Level (BAL) assessor today for more information.