What are the requirements involved in Bushfire Attack Level (BAL) of BAL-29?

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:

  1. 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.
  2. 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.
  3. 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.
  4. 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.
  5. All doors and windows must be fully covered by bushfire shutters or screens.
  6. Door and window frames and all assemblies are to be non-combustible.
  7. All glazing shall be toughened Grade A safety glass which a minimum thickness of 5 mm.
  8. Ember guards and mesh screens are to protect all openings vents, weep holes etc.
  9. Joint openings in all joinery to be kept at a minimum size as specified by the AS3959.
  10. 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.

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