Bush Fire Regulations

The standard has 6 levels of severity expressed as bushfire attack levels (BAL): •
BAL – low • BAL – 12.5 • BAL – 19 • BAL – 40 • BAL – FZ

BAL Level
Risk of wind-borne ember attack and burning debris and/or direct exposure to flames from a fire front.

BAL-Low Very low
BAL-12.5 Low
BAL-19  Moderate
BAL-29  High
BAL-40  Very high
BAL-FZ  Extreme

Benefits of Bush Fire rated screens

Comply with the building permit requirements by fitting screens that comply with the requirements of the Australian Standard AS3959-2009.

Reduces the risk that wind-borne embers or flying debris will penetrate glass and cause your soft furnishings to ignite.
Drawbacks of Bush Fire rated screens
Additional cost of fitting screens and/or materials to glass you would otherwise not have screened.
If the screen doubles as a security screen, screw attached it can become harder to clean the glass.
Because compliant screens at BAL-12.5 and above require metal mesh, the quality of finish and potential for kinks/dents, corrosion and sagging mesh increases.

What makes a screen BAL compliant?

Essentially as the BAL risk increases, more fire resistant materials are required and more glass on the building is required to be screened.

BAL-Low has no requirements at all.
BAL-12.5 requires a metal frame and aluminium mesh
BAL-19 requires a metal frame and aluminium mesh
BAL-29 requires glass below 400mm from the ground is required to be screened and the frame is to be metal and the mesh at least aluminium. The Aperture of the hole 2mm or less.
At BAL-40 both the opening and fixed portions of all glass need to be screened and the mesh must be Stainless Steel and must be fixed to windows and doors with metal fixings.

For full guidelines see the attached.